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Blood Sweat Tears and Grease => Projects => Restorations => Topic started by: medicalmechanica on Sep 23, 2016, 04:11:20

Title: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 04:11:20
Hey folks,

I just bought my first motorcycle, a 1968 CB175. I guess it's a sloper according to the year and the title, maybe someone can confirm with the only picture I have right now.

I got it from a friend for a decent price, and it's in great shape including factory paint on the tank. I've got two issues right now that I'd love feedback on, and I'm reading about this thing every free moment I have so I'm not totally helpless.

Issie one is right now my right cylinder is not running. The carb on that side was overflowing gas through the tube so I figured the float pin was stuck and replaced it, but after starting it up and having a cold exhaust on that side, I've learned that something's up. I'll be trying to run it just on the right side tomorrow with the left side spark plug lead and checking the plugs to get an idea what's up there.

I also have a leak from the camshaft block on the left side, and I'm hoping that's just a gasket issue or maybe an issue with that cover.

Anyway, it doesn't need much restoring, but it needs a little love to get moving and I'd really like to have a running bike before winter hits us so any input would be appreciated.

Thanks in advance, and I'm really looking forward to this little project!
Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 10:29:17
Yup. "Sloper". Note how the jugs angle forward instead of vertically. Great bike. TONS of info online as they are super popular machines in the vintage road race world. I actually have a 68 175 sloper motor and frame. May have to do something with it someday lol.

Looking forward to seeing what you come up with and welcome to DTT.
Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 10:30:07
Oh... And that's a CL175, not a CB.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 13:17:20
How can you tell the difference? It's titled as a CB, so it'll end up registered as a CB and I'd prefer to correct that if I can.
Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 13:21:56
CB...

Different tank, low pipes, etc...
Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 13:22:25
Check the VIN on the frame neck...
Title: Re: 1968 CB175 repair and build
Post by: advCo on Sep 23, 2016, 13:23:00
Nice little bike. For the running issue, first make sure you have a strong spark on that side like you mentioned. I would then go through the full tune up procedure: cam chain tension, valve clearances, set timing and then carburetor sync.   That should remedy your problem.


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Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 13:25:56
And a side note...

From the pic, that bike looks pretty damn clean. If it were me, I'd do a thorough cleaning. Replace what NEEDS replaced. Get it running at 100%. Touch nothing else. The early bikes are getting harder to dig up in original condition and doing a "restoration" can actually lessen the value.
Title: Re: 1968 CB175 repair and build
Post by: HerrDeacon on Sep 23, 2016, 14:04:18
Check the VIN on the frame neck...

Agree, check the VIN against the numbers shown on this site: http://www.motorera.com/honda/index.htm#y175

Also, based on the little bit of poking around I did, the CB175 wasn't built until 1969, but the CL started in 1968.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 17:18:29
Agree, check the VIN against the numbers shown on this site: http://www.motorera.com/honda/index.htm#y175

Also, based on the little bit of poking around I did, the CB175 wasn't built until 1969, but the CL started in 1968.
this helps a ton, thanks!

I don't plan to do the whole full restore thing with new paint and powder coated frames and blabla, I plan to just clean it up a bit and maybe rechrome the fenders and clean up the used-to-be-shiny bits. Honestly i wanted a 360 to do a full cafe thing with but this one was cheap and in fantastic shape, and I should br able to fix it up and double my money, plus I've ridden a motorcycle four times in my whole life including yesterday so not dying seems like a good idea.

I'm gonna hit the gym and head home to switch spark plug leads, and then tear into the carbs anyway so I'll update soon hopefully heh.

Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 17:36:03
Leave the chrome as is. Honestly man. The market for "survivor" bikes keeps growing. That American Pickers and whatever other show has everyone thinking anything untouched and older than 1970 is worth a pile of money.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 19:22:59
That's a great point I guess, and a big part of the appeal for me was that it's so clean for the age it is. I just can't stand bubbles in chrome, but as they say with these bikes you don't need to fo looking for extra stuff to do so it'll probably stay the way it is for a while.
Title: Re: 1968 CB175 repair and build
Post by: VonYinzer on Sep 23, 2016, 19:56:26
At the end if the day it's your bike. Do with it as you please. That said, you mentioned resale value. Best bang for your buck is an all original survivor that runs like a top with new cables, tires, etc...
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 20:07:45
Either way getting it running happily is the main priority heh, but i appreciate the input and it makes total sense.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 21:39:02
So I took apart the carb on the right and cleaned it up a bit, installed some of the stuff that fit, and now I'm putting it all back together. Forgive me because I don't know what some of this stuff is called, but the cylindrical part that moves up and down in the carb and is attached to the throttle cable does not move freely in the tube it goes into. Dunno what to do about that, so I'm kinda stumped.

Edit: I have learned that this thing is called a slide. The slide isn't moving freely up and down in the carb, it feels too tight. I compared to the left carb, and if I lift that slide with my finger it drops right back into place, but the slide on the right just sticks. I'm thinking that this may have contributed to my right cylinder not firing.
Title: Re: 1968 CB175 repair and build
Post by: clem on Sep 23, 2016, 22:14:07
About the model designation, it may actually be a CB.  They're were some CB's that were dressed out as CL's by dealers as an option. I don't know if that was offered by Honda due to a parts surplus or not. The vin should start with a B if it is truly a CB.

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Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 23, 2016, 22:24:22
About the model designation, it may actually be a CB.  They're were some CB's that were dressed out as CL's by dealers as an option. I don't know if that was offered by Honda due to a parts surplus or not. The vin should start with a B if it is truly a CB.

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It's a CL after all, I checked it out on the VIN decoder page that was posted.

I just found out that if the intake manifold is too tight the tube will warp a bit, so I loosened it up and my slide is moving freely again.

Now I just have to wait for the battery to charge up so I can test sparks.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 24, 2016, 16:45:39
Well I switched the spark plugs, and tue bike fired up and the right side exhaust is warm. Either it's running too lean and cool, or I just didn't let it idle long enough is a problem for another day I guess. I'm going to buy new plugs and wires just to be safe.

Now to tackle the oil leak I have. I've attached a picture of the problem area, does anyone have any idea what I should do first? Couple other pics just because haha.
Title: Re: 1968 CB175 repair and build
Post by: cxman on Sep 24, 2016, 18:24:34
if you have oil leaking near the points cover your cam seal is bad

not to big a deal

remove the points plate then then advancer and you can then see the seal
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 24, 2016, 18:44:03
Is that seal around the points cover the only thing that could be causing the leak? And is it something I can hit with some RTV for now?
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 24, 2016, 20:13:06
Alright, I removed the points cover and I'm assuming the advancer is the round thing that's right under it. I removed that and forgot how to replace it so that's a problem, and I found a yellow gasket that sits against the engine and is total garbage. Time to hunt for a replacement. Also in the last pic there's some substantial grooving on the end of the cam, is this a huge issue?
Title: Re: 1968 CB175 repair and build
Post by: advCo on Sep 24, 2016, 23:35:21
The advancer is the unit in your first photo. If everything is moving smoothly I would just grease it and put it back. That cam looks pretty rough. Go to any Honda dealers website, look up your year/model and find the correct fiche (probably crankshaft or head) to find part numbers for the seal you need


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Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 25, 2016, 01:07:01
The advancer is the unit in your first photo. If everything is moving smoothly I would just grease it and put it back. That cam looks pretty rough. Go to any Honda dealers website, look up your year/model and find the correct fiche (probably crankshaft or head) to find part numbers for the seal you need


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Thanks!
I've actually made a gasket and I'm going to give it a shot tomorrow, and I learned how to set the points so I'm going to go ahead and fix the timing and change the oil tomorrow, and grab new spark plugs and (hopefully) wires, but I doubt I'll be able to find them in town. If my gasket holds up long enough to tune the carbs I'll be pretty happy, and we'll go from there.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 25, 2016, 16:40:47
So I made my own gasket, installed the points, replaced the oil, and now the bike isn't starting. When I kick it, it feels like it wants to stsrt sometimes, but ywo new things are happening.

The first one is that I can feel a kick back in the starting lever against my foot sometimes and that didn't happen before.

The second is that I'm hearing a strange noise when I twist the throttle while I'm kicking it, like a "patuung" noise, sort of like throwing a rock into water.

I'm pretty positive I set the points correctly using a circuit light, and I also rewired the connection from the coil because it was only working intermittently. Pics are attached, any ideas?

Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 25, 2016, 17:40:51
I've opened up the points again and they're way off. I did the cam chain adjustment, but now the point is opening way too early, so I reset it to the L mark, tighten down, and then when I come back around it opens way too early again. Kimda stumped.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 25, 2016, 18:41:02
Got the points in the right spot I think, and the kickback from the starter is gone. Still not starting though, haven't been able to figure out why.
Title: Re: 1968 CB175 repair and build
Post by: medicalmechanica on Sep 25, 2016, 18:55:48
One more thing, I watched some videos of the points and timing, and I wanna make sure I'm on the right mark. Attached is an image of the plate with the timing marks on it, and my point opens at the F mark. I read that it doesn't really matter when it closes again so I hope that's correct. Right now the point breaks at that F mark.

Because the bike ran a couple days ago I'm pretty sure that the plugs and wires are okay. I'm going to replace them anyway,  but I'm thinking that the timing is the problem here. 

Any advice would be great.


Edit: I buttoned everything back up for now, got some new spark plugs in, and I'm charging the battery again because I think kicking this thing all day may have killed it.

If anyone wants to chime in and let me know if the orientation of my points plate is at all correct I'd appreciate it, I don't see a mark in the casting of the kidney-shaped cover thing that tells me where it's supposed to line up. I have a feeling that may contribute to my point opening early on the intake stroke.

Again, any advice or input would be super appreciated. Thanks!

Edit again: I learned that this bike has a "wasted spark", or a spark on the exhaust stroke, and because I only have one point and both cylinders fire as they reach TDC I'm not so worried about my "Intake" picture below. I'd still like to know if I put the plate that the point is attached to on correctly though!
Title: Re: 1968 CL175 repair and build
Post by: teazer on Sep 26, 2016, 01:22:45
A couple of things.  That is a 1968 one year model CL175 and not a CB.  The giveaways are the fact that it's a 175 sloper and not the same as a sloper CB160, plus the high level pipes and that tank was only fitted to a CL175.   Vintage racers love them because they are cheaper way to get 5 speeds in a sloper than welding and machining a set of CB160 cases. 

Other than that, there's not a lot of interest or demand for them.  The earlier CB160 is more desirable and later , so called vertical 175s were better engines for racing or fr the street.

Next: that can is stuffed.  It will not run very long with that in there.  The cam end support that you removed has to be a fairly close fit over the cam end to maintain oil pressure to the rockers and to the big ends as well.   The cam needs to be removed and repaired and so does that end housing. You can convert the camshaft to a needle roller inner race and fit a needle roller cage in the outer hosing with some careful machining.

Points should open a certain distance before TDC with both valves closed ( on compression).  Because it has a 360 degree crank, the points cam opens the points once per engine revolution anf fires the double ended coil each time.  That's known as a wasted spark system. At tickover, it should crack open at the F mark 5 degrees or so before TDC.  If it opens too early, adjust the timing.

If yiu don't have one, get a workshop manual.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 27, 2016, 00:16:11
A couple of things.  That is a 1968 one year model CL175 and not a CB.  The giveaways are the fact that it's a 175 sloper and not the same as a sloper CB160, plus the high level pipes and that tank was only fitted to a CL175.   Vintage racers love them because they are cheaper way to get 5 speeds in a sloper than welding and machining a set of CB160 cases. 

Other than that, there's not a lot of interest or demand for them.  The earlier CB160 is more desirable and later , so called vertical 175s were better engines for racing or fr the street.

Next: that can is stuffed.  It will not run very long with that in there.  The cam end support that you removed has to be a fairly close fit over the cam end to maintain oil pressure to the rockers and to the big ends as well.   The cam needs to be removed and repaired and so does that end housing. You can convert the camshaft to a needle roller inner race and fit a needle roller cage in the outer hosing with some careful machining.

Points should open a certain distance before TDC with both valves closed ( on compression).  Because it has a 360 degree crank, the points cam opens the points once per engine revolution anf fires the double ended coil each time.  That's known as a wasted spark system. At tickover, it should crack open at the F mark 5 degrees or so before TDC.  If it opens too early, adjust the timing.

If yiu don't have one, get a workshop manual.

Thanks?  I figured the cam was pretty close to dead, but I'm going to use it for a little while.

In other news, my bike finally fired and ran for a couple minutes, but the stator cover and the points cover were off, so I killed the bike and put all that stuff back on. Guess what? Doesn't start again.

A couple questions:

Should I be seeing sparks fly from the point? That doesn't seem right, my understanding is that the point opens and the arc travels between the gap.

Second thing, I had my plugs out and plugged into the leads and was getting a spark on the left and not the right. After I put the covers back on I was not getting a spark from either plug.
Am I correct in assuming that this is probably a faulty coil?

I'm pretty concerned about the sparks coming from the point, and since I've replaced the point rocker assembly with a new one I don't think that's the issue. Maybe the gap is way off or something?

I'm waiting on a service manual in the mail so hopefully that'll help
Title: 1968 CL175 repair and build
Post by: advCo on Sep 27, 2016, 00:31:25
The points will spark a bit, that's normal. If it looks like the Fourth of July, something may be wrong.

You can test coils with a multimeter., the plug wire lead and negative lead should give you a ~12-15k ohm resistance reading and between the two 18ga wires should read between 3k-5k ohms.

If you put the points cover back on and the bike wouldn't run, then your points wires are grounding out to the cover. Double up on gaskets or rearrange your wires accordingly.

As far as the cam goes, you should open up the top end and check the surfaces that the cam rides on. If you're lucky, the top end may be savable, and running that cam further may ruin a good head and rockerbox. I believe someone on here very recently had a similar problem but was able to source parts from eBay.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 27, 2016, 01:20:21
The points will spark a bit, that's normal. If it looks like the Fourth of July, something may be wrong.

You can test coils with a multimeter., the plug wire lead and negative lead should give you a ~12-15k ohm resistance reading and between the two 18ga wires should read between 3k-5k ohms.

If you put the points cover back on and the bike wouldn't run, then your points wires are grounding out to the cover. Double up on gaskets or rearrange your wires accordingly.

As far as the cam goes, you should open up the top end and check the surfaces that the cam rides on. If you're lucky, the top end may be savable, and running that cam further may ruin a good head and rockerbox. I believe someone on here very recently had a similar problem but was able to source parts from eBay.


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Super good info, thanks! I'll have to do this tomorrow I guess. As far as the cam is concerned, I have had a quick look without totally tearing the engine down and all the surfaces I can see are fine. I have probably a month before winter is here and I'll be doing a replacement of the cam then, but I want to at least see if I can get it running before then.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 27, 2016, 20:11:47
Alright, I got the seat and the tank off just to have some space.

I think I tested the coil correctly. I traced a wire coming from the coil to a "Y" or a "pigtail" (I think), popped out the connectors and tested with a multimeter between those two points. Getting a 1.8ohm reading which I'm pretty sure is bad, and I was getting nothing from either spark plug lead and I know that's bad too.

I'm guessing I should just order a new coil, and they come with wires attached, correct? I've been seeing some talk about using an Accel one for a Harley or something, anyone got info on that?

Pics attached for reference, maybe I measured the completely wrong thing.
Title: Re: 1968 CL175 repair and build
Post by: advCo on Sep 27, 2016, 22:41:02
So you have a single coil feeding both plugs, correct? 1.8 should be okay. Test resistance between the two spark plug leads.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 27, 2016, 23:31:45
I'm getting about 13k ohms from plug wire to plug wire. I was also under the impression that the coil should put out about 3.5 to 5ohm, so isn't 1.8 hella low?
So you have a single coil feeding both plugs, correct? 1.8 should be okay. Test resistance between the two spark plug leads.


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And yeah it's one coil feeding two plugs. It looks like the universal options in the DTT shop will work if it's necessary.

It seems prudent to note that I'm seeing a spark from both leads but it doesn't look too strong.
Title: Re: 1968 CL175 repair and build
Post by: advCo on Sep 27, 2016, 23:36:05
If you have spark then more than likely the coil isn't your problem. The value between the leads is good. 1.8 does seem a bit low but you need to check the values in the factory service manual. Generally if a coil goes bad, there's no resistance and no spark.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 28, 2016, 00:18:24
If you have spark then more than likely the coil isn't your problem. The value between the leads is good. 1.8 does seem a bit low but you need to check the values in the factory service manual. Generally if a coil goes bad, there's no resistance and no spark.


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Well that's a relief, thanks! I may get a new coil and leads anyway because they're not terribly expensive and I am almost positive that I should have like 3ohms from the coil, AND the bike doesn't start even with some starting fluid.

That said, I guess I'm having a fueling problem. I'm okay chasing down wires all day for the most part, but getting a set of carbs to work is over my head. Here goes nothing I guess haha

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Sep 28, 2016, 11:10:39
The trick with carbs is to get a couple of small containers - cold cut containers are fine or small baking trays and put one carb in each.  Take your time to strip and clean them.

When you think they are perfect, get a can of carb cleaner or wd40 and spray it through one jet on one carb and repeat for the jet on the other carb.  Is the spray the same on both?

After you are sure that the jets are all clean, repeat that process on the bodies.  Spray though each drilling one at a time and compare to the other carb.  That is the only way for most most of us to know they are clean.  Pay particular attention to the tiny holes in the bore just in front of the slide.  They clog and are hard to clean.
Title: Re: 1968 CL175 repair and build
Post by: advCo on Sep 28, 2016, 13:18:53
+1. I use carb cleaner and compressed air first to blow out all the passages. It's worth noting to make sure that your jets have the same numbers stamped on them on both carbs, and that all the brass is the original stuff. I can't speak from experience but I know a lot of people have issues with aftermarket brass.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 28, 2016, 16:30:46
I have a couple aftermarket brass bits in one of them, but that's kinda just what I have to work with right now, I'm going to have to get a rebuild kit too I guess.

I'm hearing some clacking while kick starting, it's happening at the end of the throw of the kick lever. On the CL175 the only place I can see something that looks like a cam chain tensioner is right in front of the engine, so I backed it out and screwed it back in, but it's still giving be a bit of a clicking noise. I'm going to adjust the valve clearance today and see if that helps, but if not I'm assuming I'll have to just tear everything down and replace the tensioner and the chain, is that correct?

If so I'll just go ahead and take it all apart and order the camshaft, tensioner, chain, and rocker arms I guess and rebuild the whole thing which I'd really prefer not to do.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Sep 28, 2016, 21:12:57
She started! A little spritz of starting fluid and a goose and she fired up. The bike won't start without full choke, and it won't continue to run without basically wide open throttle, but it's something. Does anyone have a source for like a writeup or a diagram of what each screw on the carbs do? I ask because I have no idea what any of them are for, and because my left carb is missing two near the top. 

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Edit: I redid the cam chain adjustment and I'm not hearing the clacking, and I redid the points afterwards. I tried to get the valve covers off to adjust the valves but I don't have a big enough wrench and I don't want to round them off with a socket.
Title: Re: 1968 CL175 repair and build
Post by: advCo on Sep 29, 2016, 14:56:36
Sounds like your pilot circuit is clogged still. Find a parts fiche for the carbs from any Honda dealers website it will tell you exactly what every part is.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 01, 2016, 22:40:38
Alright, so I've disassembled and cleaned the carbs for the second time now, put everything back together, installed it on the bike, balanced the throttle slides, and I can sometimes get the bike to start. It bogs under heavy throttle input, and will not start without the choke at about 90% and a goose from the throttle, and even then not every time. Both cylinders are getting warm at the exhaust, but the right side is a bit cooler so I'm guessing it's running leaner than the left cylinder. I don't really know how to adjust carbs so I'm going to have to read up on it, but at least it's something.
Title: Re: 1968 CL175 repair and build
Post by: teazer on Oct 02, 2016, 13:43:01
Did you spray through the tiny holes into the bore that the pilot jet discharges from.  They are tiny and they block easily
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 05, 2016, 23:17:32
Did you spray through the tiny holes into the bore that the pilot jet discharges from.  They are tiny and they block easily
I can see daylight through all of the jets, and the carb housing and everything is super clean. There are tiny little holes inside the opening of the carb in front of the slide, do they go straight through or are they just cast in? I honestly can't find anything else to clean because I've done both a number of times now. I'm thinking I should try swapping the carbs and starting to see if that works at all.

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Edit: When I get it started if I cover the right side carb the bike revs way up. I don't know if that's helpful, or if because the right side isn't running in basically just plugging a vacuum leak.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 18, 2016, 18:49:28
Well I was able to ride this little thing today for about ten minutes. It starts alright with no choke, but I'm still getting a much cooler exhaust pipe on the right side. The bike also bogs pretty heavily under throttle and then will catch up, which I'm thinking means it's running rich. If I tip the bike to the left it'll idle up a bit which is weird, and it really doesn't like moving forward haha. I'm getting some white smoke from the exhaust now, so I don't really know where to go from here.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Oct 19, 2016, 15:09:48
I can see daylight through all of the jets, and the carb housing and everything is super clean. There are tiny little holes inside the opening of the carb in front of the slide, do they go straight through or are they just cast in? I honestly can't find anything else to clean because I've done both a number of times now. I'm thinking I should try swapping the carbs and starting to see if that works at all.


Those super tiny holes are above the pilot jets and it's hard/impossible to see through them.  The trick is to fire carb cleaner up through the pilot jet and look to see that it sprays out of the holes - wear goggles and do that outside or with lots of ventilation.

Much cooler exhaust suggests that the pilot jet is still blocked on that side.  And yes, they are a PIA design that clogs so easily and is so hard to get clean.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 19, 2016, 16:00:26
That's super good info, thanks! I'll take the carbs apart again today and run through everything with some safety wire or something and see where that gets me.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 20, 2016, 03:25:18
Well I swapped the carbs for kicks and my cold cylinder is now my hot cylinder. This tells me that there's for sure something up with the right side carb, but I took it apart and I can't find a single spot that's clogged. Per Teazer's suggestion I blew through the tiny hole in the top of the intake side of the carb and air moves freely through that jet. The needle jet and jet needle are functioning correctly, and I know that fuel is moving through the fuel lines. I'm thinking about trying to track down another stock carb and see where that takes me.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 21, 2016, 16:40:30
Learned two things today!

Thing one, I'm retarded.
Thing two, I have a 180 main jet and a 98 main jet. My suspicion that the right side carb was too rich is true, the carb on that side had like twice as much fuel going to it. Ordered a rebuild kit and I'm confident that two 98s will do it haha. Now all I need is to find a good cam and I'll have a perfect little bike, fingers crossed.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Oct 21, 2016, 17:26:21
FYI, 180 main jet in a keihin carb 1.8mm diameter and that will flow 4 x as much fuel as a #90.  Or did it have a minkuni jet in that carb?

Go on line or contact your dealer and see if you can get two good new Keihin main jets for that carb.  Early and late Honda's use different threads - same diameter but different pitch. I can't remember which pitch the 175 used and what that is compatible with but can check it over the weekend if you need.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 21, 2016, 17:32:59
FYI, 180 main jet in a keihin carb 1.8mm diameter and that will flow 4 x as much fuel as a #90.  Or did it have a minkuni jet in that carb?

Go on line or contact your dealer and see if you can get two good new Keihin main jets for that carb.  Early and late Honda's use different threads - same diameter but different pitch. I can't remember which pitch the 175 used and what that is compatible with but can check it over the weekend if you need.
I have Keihin carbs, and I read somewhere that a 98 and a 38 are the way to go. I ordered a rebuild kit that meets the specs for the threads I have so I think it'll be good to go, but if not it was only like 19 bucks so I won't have to take out a loan or anything if I ordered too hastily.

Should I keep the needle in the 3rd notch and go from there?

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 24, 2016, 21:57:01
Aaaaaaaand I'm stumped. Both carbs are set up the same, same jets, same float bowl heights, same fuel filters which are known to work, same air filters, same needle positions, same fuel screw settings, and I'm still getting a cold pipe.

Does anyone know what operating temps I should be seeing? My left pipe is like 400 degrees and my right pipe is in the 110s.

I know I have spark. I know I have compression because I checked, and because swapping the carbs reverses the problem. I know there's fuel for that same reason. It has to be something carb related but I would eat off of both of them, and even though I have new jets I cleaned them AGAIN and ran a tiny wire through all of the ports to be safe.

Help? Thanks!

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 25, 2016, 23:53:43
SUCCESS!!

I had a tiny pinhole in my float and I guess it was sinking, fixed and fixed! Riding this thing is awesome, and now I'll have to tear it down and replace the gaskets and cam.

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Title: Re: 1968 CL175 repair and build
Post by: advCo on Oct 26, 2016, 00:28:43
Ha! Good catch. I've had that happen to me before, but it just ended up with fuel spilling all over the driveway. Glad you got it figured out.


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Title: Re: 1968 CL175 repair and build
Post by: teazer on Oct 27, 2016, 00:49:40
Cool.  One thing I try to do now is to set FUEL level and not FLOAT level.   That way, any float problems are obvious and it's what we are actually trying to do when we set the float level. 

Doing it "wet" where possible is more accurate.

A simple test for floats is to stick one into a cup of really hot water and watch for a stream of bubbles.  No bubbles is good, any bubbles is bad.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 27, 2016, 01:14:57
Yeah, that's how I found the hole once I realized what was happening.

I'm having a great time riding this thing but it's leaking oil so I should probably stop. I'm seeing oil on the kickstand and the little chain cover is impossible to get off because the PO demolished the screws, so I can't tell where the leak is.

I'll probably tinker around until my gaskets arrive and then I'm gonna just refresh everything, grab a brat seat and some clubmans and call it done.

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Title: Re: 1968 CL175 repair and build
Post by: HerrDeacon on Oct 27, 2016, 05:13:02
Cool.  One thing I try to do now is to set FUEL level and not FLOAT level.   That way, any float problems are obvious and it's what we are actually trying to do when we set the float level. 

Doing it "wet" where possible is more accurate.

That's the way Kawi does it and it works great. I found it real strange when I got my first Honda and they set them the other way. Way too much margin for error if you ask me.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 27, 2016, 14:41:59
All three of them are destroyed haha, gonna grab an extractor kit and see if that works, and if not I guess I'll have to drill them out and cut new threads in, which I hate doing.

In an earlier post I showed a picture of my camshaft end on the points side and how chewed up it was, and before I order a new cam I have a question.

If I were to cut the scoring out of the cam, would I be able to run a smaller gasket in the cam journal to make a seal? The seal is leaking a few drops into the points housing, and I'm thinking if I can find a gasket with a smaller ID and flatten out that surface it'd work fine.

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Title: Re: 1968 CL175 repair and build
Post by: advCo on Oct 27, 2016, 17:20:24
Get a drill bit that's just a hair bigger than the 6mm bolt shaft, and drill through the head of the screws until they pop off. Take the cover off, and I'll bet the rest of the screw will come out by hand. If not, vice grips.


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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Oct 27, 2016, 21:32:06
Get a drill bit that's just a hair bigger than the 6mm bolt shaft, and drill through the head of the screws until they pop off. Take the cover off, and I'll bet the rest of the screw will come out by hand. If not, vice grips.


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That's the plan! Hopefully I'll get enough of one out without destroying it that I can take it to the hardware store and get some nice new black hex hardware.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 22, 2017, 17:11:13
Oh man it's been a while. Finally have the time to get into this little engine. I ordered a camshaft today, piston rings, and a whole gasket set. Hopefully next week I'll be able to replace the cam and all the gaskets and my little scooter will be back on track.

Question for anyone interested, I've never replaced the cam in a bike before, anything to watch out for? I'm a little worried it'll be a tooth off or something when I'm done. I'm planning to put the left piston at TDC and just pop the cam out and replace the new one in the same position I guess.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 03, 2017, 15:02:41
(https://uploads.tapatalk-cdn.com/20170303/fb04b11b439b3a39c0d264c99ecc1601.jpg)(https://uploads.tapatalk-cdn.com/20170303/db6a073b84e0d07364b841f30b041c3d.jpg)(https://uploads.tapatalk-cdn.com/20170303/b13759b668a94ce199a950cdc852990c.jpg)(https://uploads.tapatalk-cdn.com/20170303/6638b13e8ab330e47de1b09a1e916f39.jpg)

Engine out! Only one deep wound under the fingernail, calling that a success. Just have to pick up a chain breaker and I'll be at least popping the cylinders off, if not getting everything back together tonight.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 03, 2017, 19:34:44
Please pick that motor up and place it on a table of some sort to keep the dust out of it.

Cam timing is easy and is spelled out pretty well in the service manual. Take the time to check the timing and ask questions if it's not clear - before you bolt it all back together.  good luck- and mind your fingers.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 03, 2017, 19:36:42
Oh the motor was on the ground for about ten seconds. I taped up the intake and exhaust before I even took it off the bike and now the motor is on a table in my living room.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 04, 2017, 02:08:46
Well, looks like I'm screwed. I got the rings on and was able to slide the cylinders back down onto the pistons but only about halfway, and now they won't go down any further or come off. Not sure where to go from there.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 04, 2017, 13:31:07
That's unusual.  Daft question, but are you sure that the cam chain or tensioner or something else isn't in the way?

Are both pistons in so that all rings are in the bores? or is it cocked to one side?  It's really hard to trouble shoot without seeing it.  Can you post a picture or two?
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 04, 2017, 15:49:27
The chain and tensioner are out of the way for sure, I can move them around freely right now because the pistons are at TDC. I've been able to see that the right piston moves but the left one is completely stuck.

Also Teazer, I heard you were a 175 expert, can you tell me which cranks will fit? I'm fine with tearing all the way down and replacing the crank, pistons, and cylinder and I'm like 90 percent sure the cylinders are interchangeable.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 04, 2017, 17:18:42
Any 160, sloper 175 and vert 175 crank will drop straight in.  Some have different crank drilling etc for lightness/balance but all will work.  CB200 would work but the rods are too long and the drive pinion splines are different, so avoid those.  The crank can also be rebuilt with C90 rods IIRC.

Any 160 or 175 barrels will drop straight on.  Same height etc.  Vert 175 have different fin shapes than the slopers but I doubt that anyone else would notice.

Same with heads.  Any head will fit BUT 160 has a tiny combustion chamber, sloper and vert 175 have very different ports.  Vert head has ports cast much higher in the head and are arguably a better head but take work to make them work correctly.  The best valve guides are CB200 which have modern seals and smoke less.

It sounds almost as if the barrels are on at an angle and have cocked on one piston.  Check and see how square they are and lightly tap them up on the low side.

Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 04, 2017, 17:38:30
Dude you're amazing, I spent hours Googling around and got about half that information haha. There were some fins broken off when I got the bike so I'm going to replace the cylinders anyway. The head is in great shape, and with a little cleaning I think it'll be just fine.

I've found a few cranks with rods on them so I'm going to just take the whole mess out and start fresh, and now I have an excuse to open the whole thing up and clean the 50 years of gunk out.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 04, 2017, 22:10:55
You're welcome.  That was the cliff notes version.....

When we built our first CB160/CL175 race bikes I collected every cheap motor I could get my hands on and stripped them and measured parts and even had a couple of heads cut into cross sections to see the differences. Fortunately there are a lot more new parts available now that when we built that first motor. 

We even have one with highly modified Wiseco Kawasaki pistons and the cylinder head welded up and machined into a different shape.  The one thing I never finished though was a decent blade cam chain tensioner design to control chain whip.  One of these days....

Check out what Michael Moore did with his 216 motor or racers like Byron Blend. there's a large pool of knowledge available now on those bikes - including guys on this forum  like Zeke and his dad Patrick who have spent many hours inside those motors and trying different things.  They even had the Bostrom boys ride one of their bikes right at 100 MPH.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 05, 2017, 00:42:10
I'll have a look for sure! I was able to find cylinders on eBay that came with pistons, and a crank with conrods so those are on their way. In the meantime I've tried to impact every single phillips screw on the case and have basically stripped all of them, so it looks like I'm gonna be drilling them out and replacing them.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 05, 2017, 13:08:58
That's not unusual.  They do tend to be overtightened and then rust in place. 

The added issue is that they are not actually Phillips screws but JIS which is slightly different in the cross head.  Drill off the heads and remove the cover and the stubs should come out relatively easily
Title: Re: 1968 CL175 repair and build
Post by: jag767 on Mar 06, 2017, 03:55:22
That's not unusual.  They do tend to be overtightened and then rust in place. 

The added issue is that they are not actually Phillips screws but JIS which is slightly different in the cross head.  Drill off the heads and remove the cover and the stubs should come out relatively easily

Funny, of all the issues I have had, this was never one of them. A good pb blaster spraying, following by going around with an impact screwdriver and they'd almost always come out, there'd be one of two I'd have to easy out, but never had to drill a head off. Sometimes I will put a gritty compound in the head, give it a little more to grab on to actually.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 06, 2017, 13:54:10
Funny, of all the issues I have had, this was never one of them. A good pb blaster spraying, following by going around with an impact screwdriver and they'd almost always come out, there'd be one of two I'd have to easy out, but never had to drill a head off. Sometimes I will put a gritty compound in the head, give it a little more to grab on to actually.
Man I wish that was the case, I've soaked them and hammered away with my impact driver and they're just stripping at this point. I got one out haha, but the rest are not making it easy.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 07, 2017, 17:12:11
Well I've gotten half of them out, and because I'm a professional mechanic I tipped the engine onto the timing plate and poured oil all over the place. Making progress!

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 07, 2017, 18:57:26
Last summer we were at the races and a buddy was having problems with his shifting and needed to replace the hairpin spring and had no oil, so we laid the bike on its side and pulled the clutch to get to the shifter.  Careful to not lose any oil.

Then we pulled the shift shaft out and stood looking at the broken spring ......................................................as the oil poured out of the hole we just left and ran around our boots and everywhere else.  We all pull a dumb move from time to time.  Stuff happens, so you clean it up and get on with life.

BTW, engines are designed so that however you drain teh oil, there is always enough left lurking inside to make a ridiculous mess at some point in the process.  I usually plop the motor into a large baking tray and that way if/when the oil leaks out, it is contained. I must remembr to take one racing this season - just in case my mate has another problem to fix.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 08, 2017, 14:44:13
Last summer we were at the races and a buddy was having problems with his shifting and needed to replace the hairpin spring and had no oil, so we laid the bike on its side and pulled the clutch to get to the shifter.  Careful to not lose any oil.

Then we pulled the shift shaft out and stood looking at the broken spring ......................................................as the oil poured out of the hole we just left and ran around our boots and everywhere else.  We all pull a dumb move from time to time.  Stuff happens, so you clean it up and get on with life.

BTW, engines are designed so that however you drain teh oil, there is always enough left lurking inside to make a ridiculous mess at some point in the process.  I usually plop the motor into a large baking tray and that way if/when the oil leaks out, it is contained. I must remembr to take one racing this season - just in case my mate has another problem to fix.
Ha, I don't feel so bad now. It's on an old kitchen table that I sawed the legs off of so it'd be like chair height, it was headed for the dump anyway so I don't really care if it's covered in oil. I got the left side of the case off last night and there's one more bolt to remove on the right, and then I guess the next step is to crack the case open. I don't think I'll be able to get the conrods off the crank that's in there now with the cylinders and pistons stuck on so I'm going to have to tap them out or something, but I just wanna tear down as much as I can and clean it all up.

If I just soaked all of these parts in like a standard degreaser in a bucket for a while would it do them any harm? I'd take out rubber bits of course, but some of this stuff is so gunky that I wanna soak it and then pressure wash it while I have it all apart.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 08, 2017, 17:31:35
If you use degreaser on shafts and gears for example, wash them in hot water and use a can of WD40 to force the water out.  Do not do that on teh crank as it will rust.  Use cans of carb cleaner from Wally World and then follow up with compressed air and WD40.

An alternative is a bath or kerosene or diesel fuel followed by WD40.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 08, 2017, 17:44:09
I was more talking about the covers, like the left and right engine covers, the head, etc. Unless I find something really concerning on the new crank it's going right in, and I really don't want to mess with any of the transmission stuff.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 08, 2017, 18:02:40
For covers you can spray them with whatever cleaner you want and then scrub them with a sponge and dishwashing soap or liquid hand soap and sprayu them clean. 
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 09, 2017, 23:07:42
Finally got those bolts out, and got the covers off. I've got the stator side of the crank loose, but I can't seem to find a way to pop the other side off. I removed the clutch plates and all that stuff and I'm down to the retaining ring on the clutch itself. Do I need to take off the whole basket? Is there a bolt hidden back there somewhere?

Also I'm assuming that the smaller rotating thing on the clutch gear is the oil filter, looks like the screw there is stripped too so I'm gonna have to drill that out. Pics soon I promise!

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Edit: Also, after hammering the shit out of the top of the piston that's frozen I got exactly nowhere, so I'm thinking that since I have new cylinders I might just drill out the pin in the piston and pop it off that way, that's my best plan so far so please suggest something better haha.
Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 10, 2017, 00:29:48
The oil filter is attached to the end of the crankshaft and should be removed for cleaning and to get the gears off that are behind it.

Then you need to remove the clutch hum and basket and to get that off, you also have to remove the oil pump.  The pump is actuated by a flat "con rod" on teh back of the clutch basket and the basket and pump have to be wiggled off together.

There is a special tool to remove the oil slinger (centrifugal filter).  First you have to remove the end cap and clip and then you will see the castellated nut which has a tab washer in one of the slots.  Bend that out of the way and either grind a socket to fit the slots or buy the toll on ebay - they are cheap.  It would be helpful to those of us not in your shop to see pictures of the things that are problems/questions. That was we can be sure we're talking about the same parts that you are asking about.
Title: Re: 1968 CL175 repair and build
Post by: K4 on Mar 10, 2017, 05:23:42
This might help with photos. It's on a '71 CB175.

http://www.hondatwins.net/forums/1-project-logs/17231-1971-cb175-k5-restoration.html
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 13, 2017, 19:56:42
This might help with photos. It's on a '71 CB175.

http://www.hondatwins.net/forums/1-project-logs/17231-1971-cb175-k5-restoration.html
Dang this is perfect, thanks!

In other news, pictures.

First one is after I finally got the jugs off and confirmed that the rings had slid off the piston and jammed between them and the cylinder. I drilled straight through the overhang on the cylinder wall and tapped the pin out because that was the only way I could think of. I feel bad about it, but it worked.

Next one is taking off the oil cup, had to drill the head off and wiggle the cap out, but it's free.

The third picture is just the other side of the motor with the timing marks. I got the bolt in the end off shortly after, so I'm gonna pick up the bolt to thread in there and pop it off.

The last one is the clutch side. Is there a bolt in here somewhere that is still holding the case together? I took off everything on the bottom and every single thing I could find that'll keep them together but I just can't seem to split the cases. The left side is split, but the clutch side won't come apart.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 13, 2017, 22:31:02
Couple of suggestions. 

Alternator rotor:  Remove the center bolts and screw in the rear axle until it bottoms against the crank and then tighten it some more.  Then strike teh end of the axle sharply and the rotor should pop off. Also remove the sprocket and circlip . 

Clutch side: remove the nut inside the oil slinger, then remove the slinger and the first gear behind it.  Then undo the two oil pump nuts (they have tab washers) and slide the clutch and oil pump off together.

Then remove the shift shaft and carefully lift it off the shift drum.
Smack the clutch shaft lightly straight down and straight up with a rubber mallet (do not use a metal hammer) and the two case halves should crack open. 

Later 175/200 motors have an extra hidden bolt hiding inside the sump plate but early sloper motors do not.


Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 13, 2017, 22:43:34
Couple of suggestions. 

Alternator rotor:  Remove the center bolts and screw in the rear axle until it bottoms against the crank and then tighten it some more.  Then strike teh end of the axle sharply and the rotor should pop off. Also remove the sprocket and circlip . 

Clutch side: remove the nut inside the oil slinger, then remove the slinger and the first gear behind it.  Then undo the two oil pump nuts (they have tab washers) and slide the clutch and oil pump off together.

Then remove the shift shaft and carefully lift it off the shift drum.
Smack the clutch shaft lightly straight down and straight up with a rubber mallet (do not use a metal hammer) and the two case halves should crack open. 

Later 175/200 motors have an extra hidden bolt hiding inside the sump plate but early sloper motors do not.
Thanks!
I guess the question is, as you confirmed I don't have any secret bolts, do I need to actually remove the alternator rotor? My new crankshaft already has one attached. I'm assuming I'll have to pop the clutch basket and the oil slinger off and I'm waiting for the little wrench for that castle nut to come in the mail. Now that I have the jugs off, once I get the case open I'm going to have to take everything out of them so I can clean them out, but I can just skip the alternator rotor step right?

I'm gonna have to pinstripe your name on this bike somewhere haha, thanks dude.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 14, 2017, 17:31:46
IS there an oil seal behind that alternator and how will you replace it on the crank you plan on using?  Just looking ahead a couple of steps.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Mar 21, 2017, 20:40:41
IS there an oil seal behind that alternator and how will you replace it on the crank you plan on using?  Just looking ahead a couple of steps.
It looks like I can use my original crankshaft after all, so this one will hopefully go to a good home.
On the other side of the engine, the oil slinger thing is really on there so I'm gonna need a really big breaker bar or something since I don't have any air tools here. The case is split everywhere but behind the oil slinger and clutch basket so maybe there's something back there holding me up.

I'm frustrated haha, I know that if I could split the case and clean it I'd have it back together in a couple hours so this thing is driving me nuts.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Mar 21, 2017, 22:50:48
Did you pry back the tab of that lock washer in the slots in the castle nut?  After that, take the tool plus a short extension plus a short bar and smack it with a rubber mallet.  One quick blow should get it free.

Then thread an 8mm (IIRC) bolt into the center of the slinger to pry it off the crank. 

Then remove one primary drive gear

Then remove the clutch basket plus oil pump (two nuts plus tab washer)

Then the two halves should split.  Sometimes you have to strike the crank upwards with a rubber mallet but take care and do not use a metal hammer.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 04, 2017, 21:48:26
Yay!

Now if I can get the piston off the crank I'll be set to rebuild.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 04, 2017, 23:59:21
Pry both circlips out of the piston.  Heat piston with a propane/MAP/butane torch or with a heat gun or hair dryer or wrap it in hot towels and then gently knock the pin out with a suitable long (deep) socket as you support the piston from the other side.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 05, 2017, 01:51:51
I didn't think to use a heat gun, but I did hammer the guts out of it with a socket extension for a while and it's getting there.

Looking ahead, is there a certain position I need to have the gears in when I reinstall them?

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 05, 2017, 20:16:57
Not really.  The shafts just drop into the top half case.  Make sure it's in neutral and that all the gears spin.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 12, 2017, 22:39:46
Alright, after half a can of PB Blaster, a heat gun, a potentially broken knuckle, and the sacrifice of a small socket extension, the piston is finally off! I've cleaned up the inside of the cases and cleaned everything inside them, so once I've gone to the hardware store and replaced everything with Grade 8 stuff or hex bolts, I'll be ready to put it all back together.

Couple questions though.. In the pictures I've pointed out holes for what I'm assuming are retaining pins, and I don't have them. I'd like to think that they were never there, but it's more likely that I lost them somewhere. Does anyone know what they're called, or where I can get them, or at least an acceptable substitute for them? I feel like I could cut some metal rods and throw them in there but they're probably cheap enough to just buy.
In the last picture are the gear fork things, again I don't have a name for them, but what position do they need to be in when I put all the gears back in?

Thanks! (https://uploads.tapatalk-cdn.com/20170413/9698169840383bd242dfe54fad8d1361.jpg)(https://uploads.tapatalk-cdn.com/20170413/3d6b13e70028000d035c39838b9ed56e.jpg)(https://uploads.tapatalk-cdn.com/20170413/6967f13567bd8b47513404068e5ceece.jpg)(https://uploads.tapatalk-cdn.com/20170413/5ef1ccb4488e224b9b685dab5380e0e5.jpg)(https://uploads.tapatalk-cdn.com/20170413/fe257e9c26dd5d233dfa20dc006cd0e1.jpg)

PS I'm obviously going to clean the mating surfaces of the cases before they go back together. Got some honda bond somewhere to use for that.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 12, 2017, 23:15:07
Most of us call them dowels and HONDA calls then knock pins or something like that.  Last time I needed some I got them from my local Honda dealer.  Not all of those holes have pins.  On the main bearings one each are pins and the others are for oil IIRC.

The gear selector forks go into slots in teh various gears.  Two on one gear shaft and one on the other. Jiggle teh shafts and gears into place and get it into neutral and you should be good to go. 

Before you assemble it, clean the two mating faces and wipe them clean with acetone and then apply a THIN smear of Threebond to one face.  Honda twins of that era are assembled upside down.  Large blocks of wood are useful to prop up the back of the cases and don't forget to fit the cam chain and do not fit the sump plate until the cam chain is fully fitted.

Did you clean out the bottom case under those splash plates?

 
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 20, 2017, 18:07:02
Do these look right? I separated the gears accidentally and I just can't understand the service manual's instructions on how they go. One of the gear selectors is on one set, two on the other. I have no idea how to get neutral from here but I'm hoping to put the case back together today.

Edit: Yeah I did figure out how to get those plates off and clean them, and I'm working on the mating surfaces now to prep for honda bond. (https://uploads.tapatalk-cdn.com/20170420/aa9dc922923e56287ac045cee42598ff.jpg)(https://uploads.tapatalk-cdn.com/20170420/4d44fe510cf1a9636c9aa209bff85394.jpg)(https://uploads.tapatalk-cdn.com/20170420/9be96ff6ff175ee743054f22e90645c9.jpg)

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 25, 2017, 01:00:10
That looks fine.

Slip the gear shift lever on and cycle through the gears while turning one of the shafts by hand.  It will soon be obvious if they are correct.  if teh dogs hit each other, keep rotating the shaft until they slip into engagement.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 27, 2017, 00:25:06
Looks like I'm good then. Got the case back together today, and the clutch and oil slinger thing all on. I somehow got completely wrong side gaskets so I'm waiting on those and then we'll be bolted up. Pics soon.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 28, 2017, 00:54:38
Many gasket sets are for "vertical" ie 1970 on 175s.  Sloper 175 was one year only.  We use 160 side cover gaskets IIRC
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 28, 2017, 02:07:38
Yeah I can't seem to find the right shape for them as 175s, so I'm gonna have a look at the 160s and see if that works. Thanks!

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jun 24, 2017, 23:03:32
Woah been a while. I had a surprise move and a bunch of traveling to deal with but I'm nearly done here.

Ran into one snag, though. The camshaft I bought looked right, but compared to the one I pulled out there are some differences. Pics attached are all the old cam on the top and the new one on the bottom.

The thing fits in the journals but the advance doesn't slip over the small end of the new cam. I'm tempted to just bore it out with a drill press but I'm sure someone here will save me with a decent solution.

Any ideas?
Thanks! (https://uploads.tapatalk-cdn.com/20170625/63053b202476eef06796d7275fcfb4bd.jpg)(https://uploads.tapatalk-cdn.com/20170625/b016b6602d1c12e66e71e7c45da227bc.jpg)(https://uploads.tapatalk-cdn.com/20170625/3e088e5737811e2c275450d64492ce2c.jpg)(https://uploads.tapatalk-cdn.com/20170625/d346ea29de238093586417eae0bddc57.jpg)(https://uploads.tapatalk-cdn.com/20170625/6e1b0869c78f9cb0636c6938f31894fd.jpg)(https://uploads.tapatalk-cdn.com/20170625/f31ad1e4626597b7d675a2884ed38548.jpg)

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Edit: The new cam has R6 cast into one side of it, not sure if that helps anyone, but if anyone knows what it is I'd like to get rid of it haha
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jun 28, 2017, 19:10:13
Well I ordered a new camshaft and it doesn't fit the advance plate either, so now I wondering if maybe I had the wrong cam to begin with, or if it's possible that the 68 cam is somehow different from the later models. Anyone got any insight on that?

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 05, 2017, 02:59:52
Progress! I got a new advancer and it fits the cam I bought. It looks like this bike had maybe the wrong cam in it when I got it. My understanding is that the 306, 307 etc casted advancer belongs in the 175s and the one I had said CB93 on it so I dunno.

Anyway, just have to sinch everything up and find a tiny bolt to hold the points plate down and we'll be good to go!

Scissor jack from my 88 Supra ftw.
 (https://uploads.tapatalk-cdn.com/20170705/73c111d66be5e3bfa86648589ef37925.jpg)(https://uploads.tapatalk-cdn.com/20170705/78e85988f7d002f3bcf1946e43bdf8d7.jpg)(https://uploads.tapatalk-cdn.com/20170705/fc5531f37d9e69fc38ea8b8c83adcfbf.jpg)(https://uploads.tapatalk-cdn.com/20170705/09363e493b316d2b319930eb54f11f69.jpg)

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 05, 2017, 16:17:22
Just got back into town after a week without much internet.  Early cams - 160 and sloper 175 had a smaller diameter points cam.  Later ones were 1mm larger. 11mm vs 10mm I think.

CB93 was the 125 version of the CB160 and that's what the points assembly were on slopers of all sizes - 125, 160 and 175. Later Honda changed to use the model code 268, 259, 312 or whatever and they use that code in the part number.

You can also use a rev counter on that slotted later cam. You will need the whole cam tower assembly with gears, cable and a suitable tacho.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 05, 2017, 16:20:46
Just got back into town after a week without much internet.  Early cams - 160 and sloper 175 had a smaller diameter points cam.  Later ones were 1mm larger. 11mm vs 10mm I think.

CB93 was the 125 version of the CB160 and that's what the points assembly were on slopers of all sizes - 125, 160 and 175. Later Honda changed to use the model code 268, 259, 312 or whatever and they use that code in the part number.

You can also use a rev counter on that slotted later cam. You will need the whole cam tower assembly with gears, cable and a suitable tacho.
I'd need the new tower, gears and cable for a tach, but it should work at least to get it running again right? I've got it all back together and it seems to fit just fine so I gonna grab some hardware tonight and see if I can get it started.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 05, 2017, 23:48:07
Well, oiled and gassed up and I kicked my guts out but no start. I've got spark from both plugs, checked and double checked the points, played with the choke, and nada.

I tried to do the old finger in the hole compression test and didn't really feel anything, maybe somehow I messed up the rings. I'm also a little worried that my cam is a tooth off or something because it's firing enough for a warm pipe but it won't run.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 06, 2017, 14:22:28
Now that I think about it, it'd make more sense that I put the cam in wrong and the valves are open on the compression stroke or something. Guess I'll tear back in there and redo that and the points.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 06, 2017, 14:45:55
Before you tear it all apart, did you check that spark happens at the T position? Are the carbs getting fuel and are the jets etc all clean?

At TDC, what is the position of the points cam?
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 06, 2017, 14:51:24
The spark happens at the right spot for sure, checked that twice. The carbs are clean because I cleaned them when I removed them, and I'm getting a gas smell on the plugs. Since I'm not feeling any compression on the plug hole when rotating I'm assuming the valves are not closed on the compression stroke. I installed the cam with the O at the top but I don't remember checking what stroke I was on and I bet I messed that up haha.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 06, 2017, 14:52:43
Oh, also I'm getting that kinda bung noise when kicking on every 3rd rotation or so, which is indicative of timing, and since my spark is happening on time that'd point at the cam too right?

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 06, 2017, 15:35:37
That's odd.  The points cam is keyed to the camshaft, so in theory if the ignition timing is right, the valve timing is also right. 

The crank is 360 degrees and both pistons rise and fall together. The coil fires both plugs at the same time just before TDC, so if the timing is 180 degrees out it should still be right. At TDC one side whould have both valves open on overlap and the other side should have them both closed at TDC.  You might try removing the valve caps and at TDC see that one side there is play and on the other side, both valves should be open.

How did you clean the carbs?  Those crabs have a bypass pilot circuit that's a tiny hole on the engine side of the slide and they clog up pretty regularly. Pull the carbs and blast cleaner through that circuit and do it on both carbs to compare sides.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 07, 2017, 21:20:43
Well for giggles I redid the points because I was getting a kick back in the kickstart lever, and that's gone now. I gapped the point to whatever it is, can't remember now, while on the high point in the cam, and rotated the plate so it just breaks at the F mark on compression.

Occasionally I'll get about ten revolutions if I kick it hard, but it won't start all the way up.

I'm gonna have a look at the carbs this weekend but I'm 99% sure they're clean because I pulled them off and cleaned them, and kept them in an empty toolbox drawer while I was rebuilding.

I did actually feel compression with my finger on the left side but I'm gonna test both cylinders this weekend too just to make sure I didn't fail at the rings.

I also charged the battery up and I'm getting spark for sure.

It has to be carbs, rings, or cam timing right?

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 07, 2017, 21:23:19
By the way Teazer you're a fucking legend dude, thanks for helping me out so much.

I run a screen printing business, so if you send me a good shot of your favorite bike I'll put a white print of it on a shirt for you free of charge, you're saving this bike haha.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 08, 2017, 00:49:25
I can't get the front valve caps off, but at TDC I have one rocker slack and one tight on the intake side.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 15, 2017, 11:37:05
At TDC on compression, both are closed and at TDC on the other side, both should be open more or less the same amount. Rock it slighl forwards and if the inlet valve on that side continues to open, it's probably OK. Rotate it another 300 degrees or so and see when the inlet valve cracks open.  Should be close to TDC.

Try squirting a small amount of STerter Fluid into the intakes and see if it fires.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 24, 2017, 22:23:43
I just tore down the right side carb and it's squeaky clean. If the tiny pilot jet you're talking about is a little hole behind the seat for the needle, it seems clean and I ran a wire pretty deep into it to check. With a little starting fluid I get a warm pipe from the left side and the left carb is also super clean, but the right side pipe doesn't warm up. I got it to fire a couple times but it won't idle, and dies immediately when I give it any throttle.

I have a few print projects I'm working on so I haven't had a ton of time, but I found the wrench I use to get the tappet covers off so I'm gonna do the valve adjustments and make sure they're doing the right stuff at the right time this week.

I've got a little fantasy of taking this thing to a local bike show in September and I really hope that happens.

End of the day it has to be cam timing, compression (borrowed a compression tester and forgot it at my buddy's house haha), or maybe fuel but it seems like it's getting gas.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 25, 2017, 00:17:13
sounds like the slow jet circuit is still blocked.  Remove both carbs and strip them completely.

Spray WD40 or carb cleaner down the hole that the air adjustment screw was in.  it should squirt out at the filter side and out of the hole that teh pilot jet was in.  Repeat on the other carb.  Do they both flow more or less the same?

Now spray up through the hole that the pilot jet was in and repeat on the second carb and compare. Do NOT poke wire through jets or drillings.  It will tend to open them up and we want them stock sizes.

Do the same through each of the air drillings and compare one side to the other. 

Also look carefully at the tiny hole on the floor of the bore roughly in line with the front edge of the slide.  You should get spray coming out of there.  That's where the pilot jet flows out into the airstream.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Jul 30, 2017, 22:19:46
Alright well I don't have a screw in compression tester handy but with the press in one with the rubber funnel I'm getting 60psi on the left side and nothing on the right. I know without screwing in the gauge these numbers are sketchy at best, but nothing at all on the right side probably isn't wrong.

If I could get the tappet covers off of the exhaust side I'd know if the valves were closing, but I'm more inclined to think it's rings at this point.

Gonna pop the engine out again and work my way back to the rings I guess. What's the spec for the inside diameter of the cylinders? And what's a good source for new rings? The ebay ones I got before these were crap.

This will also give me a chance to double check and make sure my cam timing is right on the way back up I guess.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Jul 31, 2017, 13:33:59
That should be around 120-140psi with throttle wide open, so 60/0 is low for sure - assuming you are using a good compression tester.  Some ebay units are total junk and read way low.

When you pull the head off, try the old gas in the combustion chamber trick and see if any seeps out though the ports - one side at a time or with the cam out of course. 

Stock bore is 52mm on all 175s.  Honda sell rings and they are usually available on ebay.  Inspect the rings and pistons as you remove the barrels and see if they are broken or stuck in place.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Aug 15, 2017, 19:55:23
Alright, had some time today to get into this thing. I haven't taken the engine all the way off again but I got the valve cover off, or that whole cast piece I guess. These pictures show the camshaft position at the T mark on compression. Looks pretty good to me? Makes me think it's a piston issue after all.
I still can't get the tappet covers off because I keep forgetting to get a socket big enough, but just touching the rockers at TDC and they're all tight except for the right side intake valve, the rocker there jiggles just a tad. I'm assuming that's a valve lash issue and someday I'll adjust it haha.

Any suggestions?

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Aug 16, 2017, 12:06:48
Looks fine, but the mention of tight valves is not so good.  Get a new set of valve covers and then get those off anyway you need to and set the tappets. 

If you look carefully at the last picture, the left cylinder is on overlap and both valves are slightly open.  On th right side, the motor would be firing and both valves should be shut tight.  I suspect that valve seats may also be a touch rusty from being permanently open, so if it were mine I would pop the head off and remove and clean the valves and seats.  You have to loosen the valve screws (tappets) to do that so go ahead and get those covers off.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Dec 12, 2017, 00:40:10
Over a year later! I finally broke down after putting this thing back together over and over and took it to a local shop. They checked my work and told me I'd assembled everything correctly, but the cylinders and pistons had way too much clearance. They're suggesting I pick up some 50 over pistons and have the cylinders bored/honed to match. I'm fine with that since everything else is good.

Will CB175 pistons work? Any good sources other than ebay? I'm looking to just grab the pistons, rings, pins, and clips at once if I can.


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Title: Re: 1968 CL175 repair and build
Post by: teazer on Dec 12, 2017, 01:43:55
Well, that's a classic good news-bad news story.  Yes CB175 pistons will work.  I used to get all mine off ebay.

Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Dec 12, 2017, 03:15:27
Sweet! Looks like I'll be ordering a little set that comes with rings and pins and clips.
Also Teazer you're rad dude, thanks again.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 11, 2018, 05:51:01
And we're back in business! I got my scooter oiled and gassed up and put almost everything back together. The exhaust isn't totally mounted yet because I'm waiting on crush washers, and one of my bowl gaskets is messed up so that's on the way too. While dumping gas everywhere out of that carb, I was able to kick it and start it right up.

Made sure the back wheel is aligned and reinstalled the chain, and finally got it to move under its own power for the first time in who knows how long, even if it was only about two feet in my garage at like midnight haha.

Aside from the gaskets, I have to pick up bolts for the points cover, and that's the last bit.

One quick question for whoever is still listening haha, my clutch is a bit sloppy. The lever doesn't return all the way and there seems to be a ton of slack. I adjusted it at the handlebars as much as I could, but I'm thinking it's routed wrong. It should go in front of the fork, but where does it go after that? If I remember right it's down through frame where the coil is, and the just out to the left to the actual clutch actuator. That's how I have it now and it seems like I've got a good half inch of slop. May be that it's just stretched out and old, or I have it going through the wrong spot.

Pics coming when it's cleaned up a tad and all the way back together!

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 13, 2018, 19:59:11
I looked into the clutch cable routing and I have it right. I'm missing the little clamp that goes on the back of the clutch adjuster though so I'm looking for that but I can't find what it's called. EBay searching continues while the gaskets are on the way. I also found that the collar washers on my exhaust are too long, so I'm going to trim them down.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Feb 13, 2018, 20:59:27
The part is still available 22844-200-000
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 14, 2018, 02:06:35
I actually found it again in a box in the garage. It just sort of fell out of the case when I opened it up and I didn't know what it was, so I put it somewhere "safe" and it took quite a while to remember where haha. Just waiting on carb bowl gaskets now.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 14, 2018, 19:38:28
Alright, got my gaskets, popped on the exhaust and the float bowl that was leaking and that problem is solved.

I've got some oil seeping from my tappet covers so I'm gonna get gaskets for those, looks like the shop that did the cylinders might have torn them up.

Also, I'm only getting throttle response when the bike is on the kickstand, which tells me maybe something is up with the right hand carb. I temp gunned the pipes and the one on the right is a bit cooler. When riding, the engine bogs under throttle so I'm assuming my carb adjustment is just way off.

How much will 50 over effect my tuning?

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Feb 14, 2018, 19:51:02
0.5mm oversize pistons should make no measurable difference to tuning. That's around 20 thousandths of an inch.  Not an issue. Fitting 57mm or 61mm pistons might make a difference though. :-)

Check tappets and try to get new pilot jets if they are available.  And check carb synch and valve clearances too.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 15, 2018, 04:00:03
The carbs are synced, I checked that today. The shop did check valve stuff, so I'll have a look but I'm pretty sure they're fine. Because the bike responds great to throttle when it's tipped on the kick stand I feel like it's a carb issue. I'm going to open the carbs up and give them another good clean. It seems like when I'm trying to ride it it's just bogging down like it's way too rich or something.

I messed around a tad with the adjustment screws and didn't see any difference. I read somewhere that it's possible those circuits are clogged and it's just running from the height of the slides? I can't seem to find a labeled diagram of the carbs and I always forget which screw does what.

Also haha, I can't even imagine a piston that big in this little thing, that seems like way too much lol

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Feb 15, 2018, 11:05:05
We have a CL175 with 61mm pistons in it - along with a truck load of welding and machining.

If you look at the carbs, there should be 2 screws.  One is just in front of the filter and that changes the amount of air drawn in through the pilot circuit.  The one in front of that in line with the slide lifts the slide and is called the idle speed screw.

The air screw should be screwed in until they lightly bottom out and then back out one full turn plus a quarter turn. The idle speed screw start by screwing them out and then back in until they just contact the slides and start to lift and then add one turn.  That should get you going.

Yes the carbs have some very small drillings inside and they have to be clean.  Fortunately they are simple carbs.  Strip them completely and spray carb cleaner (in a well ventilated space) into/through one drilling and then repeat on the other carb to be sure they are both similar. Those carbs have tiny holes in the floor of the bore at the front edge of the slide that are easily clogged and they have to be clear. That's where the pilot jets spray fuel out and if they are not clear, no idle.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Feb 15, 2018, 14:52:51
Sounds good! I'll be trying to get into it a little on Friday probably. The bike idles just fine, and when it's leaned on the kickstand it revs right up if I rip the throttle, but if it's upright like I'm riding it it just bogs down. I'm also going to check the petcock, and maybe swap carbs and see if the problem follows.

Does that 175 have the same stock crank in it? Is the stroke the same and the chamber is just bigger?

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Feb 16, 2018, 17:14:14
If it revs faster on the side stand, it could be that the right carb float level is too high or it's flooding.

Yes.  Our 240 motor has a more or less stock crank. Stock stroke but I probably selected the lightest crank and that may have been a 160 crank.  Can't remember now.  Stock sloper 175 is a good motor. That motor has a Cb200 head with seals n all 4 valves and the  combustion chambers were welded up into more of a bathtub shape with low crown pistons to improve flame propagation.

I do have a lightened 180 degree crank here but not in a motor until I work out a better way to control cam chain whip. I'd like a gear driven cam but will probably just use modern bike tensioners and guides to calm things down.   
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 01, 2018, 19:02:17
So it turns out I'm missing this screw. It seems to block the passage to a tube in the bowl of the carb. What does that screw do? I was looking at parts fiche blowups and it's just listed as a screw, no name.

Here's hoping that's the problem. Gonna try to find something close enough tomorrow.

Edit: my bad, circled the wrong thing. I'm missing the screw pictured, but it goes in the other hole on the carb missing it.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 01, 2018, 19:25:56
That hole in the bottom carb is probably closed.  Carbs are often cast in a way that allows the same casting to be machined for left side or right side fitment. If that hole is not open to the throat, then it's OK.  That's where the air screw fits and there should be one only on the left of tht left carb and right of the right carb.

That light colored screw in the top carb is a blanking screw and closes off that passageway.  It will be a fine thread and it blocks off that passage that could be used for a Power jet.  On some early carbs, Keihin fitted a power jet to make teh top end richer for more power at the top end, but not all crabs were drilled and tapped. I believe you will find that there is a jet inside there.
Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 02, 2018, 14:22:32
That hole in the bottom carb is probably closed.  Carbs are often cast in a way that allows the same casting to be machined for left side or right side fitment. If that hole is not open to the throat, then it's OK.  That's where the air screw fits and there should be one only on the left of tht left carb and right of the right carb.

That light colored screw in the top carb is a blanking screw and closes off that passageway.  It will be a fine thread and it blocks off that passage that could be used for a Power jet.  On some early carbs, Keihin fitted a power jet to make teh top end richer for more power at the top end, but not all crabs were drilled and tapped. I believe you will find that there is a jet inside there.
Right. The big screw in the carb on the top blocks off a passage to a tube that goes into the bowl. I'm missing the corresponding screw on the other carb, I just took the picture like a spaz haha.

Would that screw missing from the other carb be causing me problems? I'm gonna try to replace it anyway, but I hope that'll solve the problem. The bike only likes to start with the choke on right now.

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Title: Re: 1968 CL175 repair and build
Post by: medicalmechanica on Apr 02, 2018, 22:41:41
Alright more weirdness! I put the carbs back on and can start the bike with the choke on.

I lost the bar that goes between the choke levers somewhere so I just open them both manually. The left jug wasn't getting hot after a couple minutes of running, so I killed the bike and pulled the plug to check for spark, which I'm getting plenty of. After I put it back together again I started the bike and if I choke the left carb the cylinder gets hot, but if I don't choke it it doesn't run.

I seated and backed the fuel mixture screws out to like 1 1/2 turns each to start, and the slides are synced so I don't even know now haha. I know it's close, and I'd really like to scoot around but this is driving me nuts.

Gonna open up the left carb and check the floats and float valve /again/ I guess.

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Title: Re: 1968 CL175 repair and build
Post by: teazer on Apr 03, 2018, 00:31:19
The bike will suck air if that top aluminum screw is missing.

See if you can get one from CMSNL.  The best way to set fuel level is to look at FUEL level and not float level.  You need  a spare float drain screw.  Drill it and insert a thin tube and connect that to some clear tube. Fuel level on both sides should be the same and around 3mm below the gasket face.

like this https://www.kzrider.com/media/kunena/attachments/6412/cleartubecombo.jpg

http://ww2.justanswer.com/uploads/MO/motoforge/2012-11-25_010502_float_level_adjustment.jpg