CL350 Junker Wrenching

MandoSteve

New Member
Hey all. I’ve checked your boards and I’m pretty sure that what I’m doing probably fits into the “Specials” category. A couple of weeks ago I was blank-staring at the shed beside my barn and suddenly thought...why don’t you see if you can make a bike out of that 350? So, here I am.

A little background on me—I’m a small engine repair guy and I like to tinker around a little with other things. I can weld, bend a little, know how to use tools. I don’t have immensely shitty taste so I might be able to get something done with this bike.

A little background on the...patient? It’s a 1973 CL350. I took it as partial trade for a repair on a garden tiller. Not a bad deal, even though at the time I thought it was pretty lousy. The previous owner said he had left it exposed over a winter and then tried to start it, which didn’t work out. Shocking. After that it had gradually sunk into mud and been lightly hit by a student driver trying to do a 3-pointer. It last turned over in 1989.I wish I had photos of its original condition, but I wasn’t really thinking about a project at the time.

So here’s where I am with it. The bike’s front forks were damaged beyond repair as was the seat and part of the seat’s mounts. The tank was full of brown sludge and rust. The keys are long since gone. The tires dry-rotted years ago, as did most of the cables and hoses. The ignition is most definitely not kicking—I even jumped the solenoid with a screw-driver and a battery pack and it seems dead as a hammer. I compression tested it though, and got almost a 100 on the first kick try, which I think is pretty damn considering it’s state. You get an “ear” for these things and it sounded good and throaty to me. The screws for the oil filter, the starter, and some others are stripped and will need to be drilled out. The headlight is shattered as is the headlight cone. At some point someone hacked the ends off the mufflers, presumably to get at the baffles. The good: the engine seems serviceable and the frame is straight. I’ll have to take it from there.

Current progress is this: I broke down the carbs first and started a list of “do before cranking” items. The carbs were...dead inside. Just dead. Took a bit but I got them cleaned and mounted.The list has veered off-course as I have experimented with one thing or another, but it has mostly stayed true. I traced out the wiring harness and put the volt meter on every end and it seems sound. I swapped out the coils, cleaned the points, replaced the fuel lines and started looking at my junk pile for possible part donors. I cut out the original battery/air box rig and slapped some cheap pods on there. I’ll switch to something else if I can get it turned over and retune it accordingly, with new jets on the carb if need be. I went down the frame removing some excess mounts. I know for some this is heresy, but I can make whatever mounts I want or steal them from other junkers. I didn’t want them clouding up my thinking when it came to fabricating/placing things like an electronics or battery box.

I started looking at what might be compatible with the front end and wound up pulling the forks and stem off a 2000 GSXR 650. I was just going to leave as-is, but the cables had already been pulled off the handle-bars. One switch set was gone, and the other seemed hopelessly frozen. I figured it was worth the experience. I ordered the right bearing set and pressed in the new stem (this was the “deviating from the list” part). I pulled the tank off and sanded it and shot on some primer to stop any flash-rusting, then used acid to clean the rust. I poured in some 50:1 to coat the tank until I am ready to use it. I replaced the pet cock as well. The other was in absolute shit condition. I didn’t see any point in rebuilding it. I purchased a battery, a replacement headlight and throttle and will throw those on later. I swapped the coils, plugs and wires. The others were fairly shitty as well.

Things I am currently sorting out in my noodle:
I have Suzuki forks. How best to mount the wheels/how will I replace or modify the hubs? Should I buy some solid rims and chunk the spokes? What are the dimensions on the rear axle? Will the swing arm require modification to accommodate a matching solid wheel set?
Can I make a proper seat tray using fiberglass (pretty sure I can). What paints are best? After a little test run, epoxy-based on the frame seems workable. It resists scratching pretty well. High-heat should work on the engine, but a few tests with the cap on the generator tells me that it’s pretty scratchable. Maybe I’ll just polish it as best I can.

I’ll update as I roll along. I’m not really making a rat-bike. I’m salvaging what I can, but I do intend to make it look as nice as possible, so plenty to blank-stare at. I brought the rear shocks and fenders home from the shop today. Shocks and springs are cleaned, the fenders were acid-bathed to break the rust. I wire-wheeled them and primed them. The chrome look really isn’t salvageable. I don’t know if I will use them but it’s productive.
 

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MandoSteve

New Member
No joke, it took hours. Overnight soak, a metric ton of acetone. I finally got down to cleaning it with a dental pick.
 

pidjones

Well-Known Member
" I don’t have immensely shitty taste" - Really? They've let me hang around, so.... I sounds like you have the right attitude, skills, and training. You should do more than fine. Heck, I used lacquer paint and the bike still turned out better than I hoped.
 

MandoSteve

New Member
Problems on this one today. I added some clip-on’s and set up the throttle and clutch just for ease in testing the engine and suddenly I can’t get the kick-starter to engage. My intuition tells me that this is no coincidence coming on top of placing a fairly shitty clutch cable into place. It’s rust af but I figured it would work. Maybe the tension on the cable is causing it not to engage fully? I don’t know for sure. The kicker doesn’t seem junky under my foot and I hear what I would consider a proper ratcheting attempt to happen. It snaps back into proper position, so the return is ok at least. The e-start isn’t an option at the moment as it seems completely dead. I suppose tomorrow I will get in there and poke around if I can get the stripped screws out. Who knows, maybe these two problems are related? Possibly. I have a starter rebuild kit, so it might be the right time.

I worked on some cosmetic items prior to that, and I’m still relatively in neutral—pardon the pun—about what to do on the axle/hub/wheel selection issue. I’ll work it out, I suppose.
 
The old honda front hubs can be modified to fit a newer front end. It takes some time and a lathe, but it can be done. The picture is a 76 cb550 hub, on a 2012 zx6 front end, with a ducati rotor, lined up with a yamaha caliper.
 

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MandoSteve

New Member
Nicely done. I have access to a lathe. By that, I mean its parts are in a storage bin. I’ll have a look and see what I can do. I haven’t fooled around with one much, but I think I could sort it out. I out my time in today on a John Deere riding mower and a nice ATV with a Honda pull start in it. I had to save the 350 for last. Curiously, when I cracked open the cover over the front sprocket and clutch adjustment I found that it was full of rat droppings...and of all things, chewing tobacco. I guess some previous owner liked his Redman, and apparently his rat did too. I wish I had taken a picture before I brushed it away. It was a little startling. I went ahead and pried the cover off the starter side as well, trying to preserve the gasket. The whole area will need a thorough cleaning and regreasing. I thought the contrast between the exposed area and the sealed side was pretty remarkable. I removed the coils and gasket and preserved them carefully. They are in fairly good condition. I decided I would go ahead and take off the after-market dirt bike kickstart that someone tacked on there long ago and it took some doing. It’s really far too wide to be sitting there and I’ll need an appropriate copy or original part. The bolts on that side are chewed as they can be. I tried an impact driver and it still wasn’t having it. I covered it with some PB and I’ll see if they can be convinced tomorrow. I suspect the clutch is shitty, and I further suspect it has never been maintained properly. As soon as I can snag the spanner for the oil filter I’ll break the entire right-hand side down and see what’s going on in there.
 

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pidjones

Well-Known Member
Amazing how poorly folks can treat equipment (but, I'm sure you've seen many examples). Just as amazing is how nice patience and the secret ingredient can make them awsome again. I'm on my second "rescue" of a bike. I think the next project (years off) will be a restoration - MUCH harder!
 

MandoSteve

New Member
Yes, this bike shows a lack of maintenance all the way around. I suspect that I will find that the filter has never been cleaned, provided I can ever get the bolts out. I called a uncle on the Impact driver and got after them with a grinder and drill today, being careful not to damage the case and using a magnet to collect metal shavings. I wasn’t in any particular hurry. Still three more to go. I have only a rear wheel at the moment so getting the foot peg/kick stand assembly was a trick being that I have the bike on a jack. I should be able to crack it open tomorrow if this Honda ATV I’m working on cooperates and starts. Speaking of a lack of maintenance...
 

teazer

Active Member
DTT BOTM WINNER
Rat_ranger said:
The old honda front hubs can be modified to fit a newer front end. It takes some time and a lathe, but it can be done. The picture is a 76 cb550 hub, on a 2012 zx6 front end, with a ducati rotor, lined up with a yamaha caliper.
Ah now I get it. Those are what they call upside down forks........
 
Lol, it was easier to check fit that way. My measurements were based off internet reading, and measuring bearings and spacers.
 

teazer

Active Member
DTT BOTM WINNER
I get it.

At one time that was the only way I could true wheels. Now I have a jig and it's still the same process.
 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Rat_ranger said:
The old honda front hubs can be modified to fit a newer front end. It takes some time and a lathe, but it can be done.
Yes, yes they can...

 

MandoSteve

New Member
Got some forward progress today. My spanner arrived, so during lunch I took a moment and drilled/ground off the old cover bolts over the clutch plates. I was pretty surprised to find very little metal in the bottom. Ideally there would be none, of course, but I’ll take what I can get. Planning on getting calipers on those plates in the morning and making sure they are true. Just from a first look, I think someone packed a school lunch brownie into the oil filter. It has never been cleaned, I’d wager. The design here fascinates me. Very clever on the part of the Engineer who came up with this. I’m an engine guy, and I really like what they’ve done here.

I pulled off the exhaust pipes and I think they are salvageable. They have some rust, but I think I can remedy that and get them ready for replacement. The style seems to be to wrap these, but I’m on the fence.

I’ll probably spend a little bit of time polishing the left and right cover tomorrow. I know cosmetics can usually wait, but I have found that doing that tends to make me push my llimits on a repair. Otherwise, I’ve wasted time...and as a poet once noted, time is the fire in which we ALL burn.

Going to polish around those two gouges. That’s character.
 

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trek97

Well-Known Member
DTT BOTM WINNER
I would just sandblast the crap off them headers, spray w VHT Fireproof black then wrap them.

The wrap can hold moisture and rust em right through.

Or you may find you like em black without the added expense of wrap.
 

MandoSteve

New Member
Aye sir. I have some black wrap and I also have some VHT. I might go that way. Got into the right side today a bit. Removed the clutch friction plates and springs before I had to go back to the John Deere with the bad fuel pump. He pays the bills.The odometer on the bike read 11k miles when I got it, and I don’t think the cover has ever been removed. Someone gave it a go in the recent past and just stripped the hell out of the hardware. 4 into 1 to the rescue. I got the hex stainless stuff from them.

Anyone ever tried Marvel on their case covers before sanding them? I just ask because I tried it on those header pipes today and it worked like a champ. I wire brushed them just afterwards and the difference was pretty amazing. Curious to see what it would do to that oxidation on the aluminum covers.

There was a fair bit of metallic sludge in the filter. That’s the sort-of bad news. I didn’t see any alarmingly sized fragments. I suppose any metal at all is cause for some alarm, but given the overall condition...I’m guessing it’s a runner. I’m use to seeing some in an old engine. It wasn’t enough to make me gasp. I’ll put a caliper on the discs and springs tomorrow and continue the disassembly on that side so it can be thoroughly cleaned. A full rebuild would make me sleep better, but I’m going to back-burner that until I get all the other pieces in place.
 

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trek97

Well-Known Member
DTT BOTM WINNER
Ive changed springs and discs in all my bikes, after discovering my 360 was slipping a constant 500rpm at 60mph.

And I didn't know it. Until I changed them out doing a rebuild. So thats a must do for me now.

My fave springs are the Heavy Duty CB350 springs made by Bore-tech. (Even fit them in my 72 CL100 ;D )

Bore-tech is currently in the process of closing shop due to health issues. They wont be available after they sell out current stock.

So I got a couple spare sets on the shelf.

Link... https://bore-tech.com/product/350-clutch-springs-cs-4

I just stick w OEM Honda discs and plates.
 

MandoSteve

New Member
Yessir, they are all gone already. I’ll keep an eye out and will likely replace both the discs and springs. I got into it a little more today. The oil filter was stunningly filthy...and then there was this. See picture—the drive gears appear to be misaligned on the shaft. I took a tentative move at shifting them myself to make sure I didn’t shift them pulling off the filter, but they seem pretty well together. Obviously, that isn’t right. I’m a relatively noob on the Honda twin, but I’d say I’m fairly well mechanically inclined. That’s clearly not right. They don’t want to come off the shaft, either. I can back them off about 3/4 of the way and that’s it.

Noodling it over right now. Not sure what my next move should be short of trying to align them before removal, which seems right to me. There’s also some pretty abnormal wear on the clutch basket itself. At least it looks abnormal to me. I suppose that could be from machining, but that just seems so unlikely.
 

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