Project "Indecisive" '72 CB500 Four (laid some paint)

[danish6259]

Hey everyone!! My name's Nick but everyone calls me Danish. I picked up this 72' CB500 Four in the summer of this year with the intentions of turning it into a cafe. I had done some work to it here and there to change the style of it while still keeping it on the road but now with winter here and myself being currently unemployed, I can really spend some time working on this. I'm trying to keep the costs low so I'll be doing as much of the work myself as I can.

When I first brought it home

Doing some cleaning

Before

After

Comparison

Before

After

I did the usual first things when making a cafe. Picked up some bar end mirrors, clubman bars,smaller turn signals, new headlight bracket and threw some tape over the headlight.

Built my own seat out of aluminum plate and rode the hell out of this bike for the rest of the summer. For those of you in the Pittsburgh area, you should remember seeing my bike at the Rockers vs Mods meet in the fall. I seem to have a lot of people know me just because of that seat alone.

It had some issues here and there with running weird and just some general problems but I didn't really care all that much because I was having a blast and knew I would tear into it once winter came around. And tear into it I did

The engine had a leak at the head gasket and the guy I bought it off of had a rebuild kit but never put it on so now is the time to do it. This is my first attempt at doing anything with an engine and so far it is going pretty smooth but I have questions that hopefully someone can help me with.

On the bench and ready to go

Breather cover off

Cam cover off

Top end pulled

Left side

Right side

Left side

Right side

Cam cover and cam

Pulled the jugs off

Left side

Right side

Pulled the oil pan off. ewwww

Bottom

And pulled the last cover off

This is the point that I am at right now and now I'm not sure what to do. I was planning on taking it all the way down and split the case but now I'm not sure if I want to go that far. I was planning on painting or powder coating the case and the rest of the engine but I've seen so many nice builds that my head is full of ideas and I'm not quite sure where to go. I'd like to get the case all nice and clean but I'm not sure if it's possible to do it right now with the way it sits right now being so stripped down.
[br /]
Anyone have any suggestions for getting the rest of the oil/grease/dirt/grim/whatever off the rest of this case and the rest of the parts? I picked up some simple green and a big container to scrub down the oil pan but I'd like to know if I can do that with any of the other parts of this engine. Any pointers and help you can give me would be greatly appreciated as most of this internal engine work is new to me.

 

[03rangerxlt]

Re: Project "Indecisive" '72 CB500 Four

Love it!
Why? Cause its a CB500 Four, and thats what I've got.

Keep us updated on how you end up doing the motor. I want to paint mine, but I am on the fence about it. Just down know yet.

 

[sxecafe]

Re: Project "Indecisive" '72 CB500 Four

Great start man. Keep the pics coming.

 

[WoodsCustoms]

Re: Project "Indecisive" '72 CB500 Four

Just love the little Honda 4's! My input on doing the motor (take it or leave it, 'cuz it's your bike)-

I get a big tub (because I don't have a parts washer, on the wish list) and scrub with brushes and lots of Kerosene. Once I get the pieces good and clean I wrap them in plastic, it works for me. Also, you can take a piece of fuel line and stick it in a big box of baking soda, then cut a slit about two inches from the end (the one not in the box), then stick your air hose in the end. A ghetto soda blaster for the heads and other carbon build up. Stole this off the net somewhere?

Good luck, Also I have some tips on hopping up these motors if you are interested.

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

03rangerxlt - Thanks!!!! It seems like the 500's are popping up all over the place on other boards, which helps for getting some ideas and seeing how other people are doing work to their bikes. Once I figure something out I'll be sure to post up and hopefully it will help you get something figured out too.

sxecafe - Thank you! I've been taking pics of the entire tear down process as I've been going along and have my GoPro HD mounted on the wall above where I'm working on the engine. Once I get this all done I'll make a video showing the time lapse of the work.

WoodsCustoms - Thanks for the advice. I completely forgot about using kerosene to scrub down the case. That won't hurt any of the internal components, if there is any left in it, when I reassemble the engine?
I'm already ahead of you on the home built soda blaster. I followed this guys build here http://forums.sohc4.net/index.php?topic=65208.0 and made basically the same setup with a few changes. I'll get some pics of it posted in a little. It's worked out pretty good for doing some of the smaller pieces and I'm still messing with it to get it to work better.
Any advice to get this motor to run better would be greatly appreciated. I was having problems with the carbs for quite a while and got most of the bugs worked out on them. I know I need a new cam chain because the adjuster was the entire way out and there was a good bit of play in it when I pulled the top end.

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

Got some more work done today and took some pics of my soda blast cabinet.

Just a standard ~30 gallon storage container I picked up at Lowes for about $15. The funnel is from Harbor Frieght and has a build in screen at the bottom of it to keep clumps from clogging up the tube.

"Hand holes" are 4" pvc male adapters with long cuff rubber gloves stretched over top and held in place with pipe clamps or w/e they are called.

I had some led strips laying around that were included in an hid projector kit I retorfitted into my fz6 and I put them inside to add some nice light so I could see wtf I was doing. haha

I pulled the "feedback" motors out of an old broken ps2 controller to help keep the soda flowing down the funnel. This made a big difference!!

What I started with

End result. Not to shabby.

I learned one lesson though. It seems that the baking soda is only good for about 2-3 runs. After that it starts to get sticky and will start to clump together. Overall I'm pretty happy with how it works and you really can't beat the cost.

I started to clean the inside of the intakes. Before

After. They still look a little rough but they are nice and smooth on the inside, which is what I was looking for.

So far everything is going pretty good but I haven't messed with the engine case yet. The oil pan has been sitting for most of the day in simple green and I'll scrub it down tomorrow once it gets a nice good soak in.

 

[Rocan]

Re: Project "Indecisive" '72 CB500 Four

man that looks like an easy motor to work on!


i can see places to improve design easily...
those valves for one... smooth out those "slots" in them, as they appear to me like a place for hot spots to occur, which doesnt help with combustion at all. some sandpaper on them should do the trick.

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

Rocan - So far it seems like it is. I've never done internal engine work before but everything is going pretty smooth and I was amazing at how simple the design of everything is. No wonder these engine last forever, there isn't anything to them. haha Do you really think those slots are going to cause an issue? That is going to be the next section I'm going to work on and if getting rid of those slots will improve performance, I will smooth them out.

I did some more work this evening and decided to clean up the pistons. First I went over them, very easily, with a wire wheel to knock off all the carbon. Then I threw them into my new toy to make my life a little easier. Merry Christmas to me haha. Picked this up at Harbor Freight for a pretty good price and it has already paid for itself on the first use. I threw the pistons in along with some simple green and watched the nastiness come off.

This is the end result after hitting the tops with a brass wire wheel again to take off whatever little bit might have been left on there and to give a nice shine.
Left side

Right side

My question now is should I replace the rings while I have it apart? I wasn't able to get a compression reading before I tore the engine apart but it seemed to run pretty good and it wasn't super easy to kick start the engine to get it running.

 

[bikeboy]

Re: Project "Indecisive" '72 CB500 Four

man that looks like an easy motor to work on!

I agree. Looks to be in great condition from what we can see. The oil pick-up is usually a good indicator. Looks nice and clean from here, with only a bit of sludge.

I'm not sure taking a wire brush to those piston crowns is a good idea, but too late now I guess ??? As for rings, there's a procedure for checking tolerance in the manual. What's the bore like? No scoring? It doesn't look like your motor has had too hard a life, so you could be in luck.

Nice project. I love these bikes as well, so I'll keep an eye on this

cheers
ian

 

[WoodsCustoms]

Re: Project "Indecisive" '72 CB500 Four

Cool blast cab, that is a great idea!

I would suggest replacing the rings and getting the cylinders honed at a bare minimum, oh and use new clips on the pistons. As for the head you can get new valve seals and a cheep lapping tool and compound if you don't want to pay to have "full" rebuild done.

 

[PePe]

Re: Project "Indecisive" '72 CB500 Four

NICE BUILD!!!!!!!!!!!!!!!

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

bikeboy - The bottom end wasn't to bad there was just a little bit of gunk stuck to the oil screen and there was some sludge stuck to the oil pan itself. The odometer on the bike isn't the original and going off the mileage on the title I assume this bike has somewhere between 20-30,000 miles on it. I have no idea as to if there was any work performed on it in the past other than a new clutch being installed.

I really didn't know of any other way of getting the carbon off the pistons and that seemed to be the least damaging way that I could think of. From what I can tell the cylinder walls seem to be in good shape. I can't really see and big marks and they are nice and smooth to the touch. I also noticed there is a nice cross hatch pattern to them so I'm assuming that is an indicator to previous motor work?

Left side

Right side

What are your thoughts on the condition?

WoodsCustoms - Thanks! It works out pretty well and was pretty fun to make to. Anything that can be used to make work on this easier/cheaper is good in my book.

Where is a good place to get rings and clips at? I haven't gotten to the head yet but what would you suggest for cleaning all the carbon off? I was planning on letting the whole top end sit in simple green to help break down a lot of the dirt and whatnot on the inside and outside before I start to tear it apart or is that a bad idea? As I said before, I'd like to keep the costs as low as possible so anything that I can do at home rather than sending out to a shop would be great.

PePe - Thanks!!! I'm trying to do the best I can on this while keeping the cost down.

 

[bikeboy]

Re: Project "Indecisive" '72 CB500 Four

bikeboy - The bottom end wasn't to bad there was just a little bit of gunk stuck to the oil screen and there was some sludge stuck to the oil pan itself. The odometer on the bike isn't the original and going off the mileage on the title I assume this bike has somewhere between 20-30,000 miles on it. I have no idea as to if there was any work performed on it in the past other than a new clutch being installed.

I really didn't know of any other way of getting the carbon off the pistons and that seemed to be the least damaging way that I could think of. From what I can tell the cylinder walls seem to be in good shape. I can't really see and big marks and they are nice and smooth to the touch. I also noticed there is a nice cross hatch pattern to them so I'm assuming that is an indicator to previous motor work?


What are your thoughts on the condition?

I soak 'em in diesel, then scrub the top (gently) with scotchbrite pads.

Bore does look pretty good. I thought I saw a small vertical scratch, but could be lighting? I was thinking what with that high compression and all, that perhaps it has had some work done? Any marks on the pistons as to size? Maybe it's bored? I haven't seen notches on valves like that before. Some have them, others not? Would be good to find out the story there too?

An interesting little conundrum

cheers
ian

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

I soak 'em in diesel, then scrub the top (gently) with scotchbrite pads.

Bore does look pretty good. I thought I saw a small vertical scratch, but could be lighting? I was thinking what with that high compression and all, that perhaps it has had some work done? Any marks on the pistons as to size? Maybe it's bored? I haven't seen notches on valves like that before. Some have them, others not? Would be good to find out the story there too?

An interesting little conundrum

cheers
ian

After checking out the pistons again I found all 4 are stamped with Honda on one side and the other side had some numbers.

First set is stamped with 323 and 7 or 1? It's a little hard to tell

Second set has 323 4 and 323 2

Any idea as to what these mean and why they differ?

I looked over the cylinders again and the one has two marks that run vertical the whole length of the wall. Should that be something to be concerned about?

 

[WoodsCustoms]

Re: Project "Indecisive" '72 CB500 Four

the pistons-
I think you can still get rings, pins and clips from honda? If you are looking to go cheep I would suggest getting at least rings and clips, but if you don't want to pay to have your bores honed, you should be ok. If you have the shop manual it will give you wear limits on the cylinders (measure in a few spots).
on the head-
I would borrow a valve spring compressor or buy one. Rip it apart and soda blast(yes, knock off all the carbon) all the parts, then lap in the valves and put new seals (honda may still sell these as well). This should get you back on the road cheep and restore compression. Oh, and always go back with a new cam chain.
General-
there are lots of o-ring seals on this motor and I would suggest replacing them all, it is cheep insurance against leaks. You should be able to find a full gasket kit with all the seals (including valve seals). Check around on the net.

Good luck!

 

[teazer]

Re: Project "Indecisive" '72 CB500 Four

323 is the CB500 model number. The other digit may be a supplier or could be the way they are machined. Are those pistons all identical or are they left and right handed like a 750?

 

[danish6259]

Re: Project "Indecisive" '72 CB500 Four

Woods - I haven't looked yet but I don't see why I couldn't find the rings and everything for the pistons to replace them just in case. If anyone knows a reliable source to get these parts at let me know.
I picked up a cylinder hone and did the work myself after doing a little research. I thought it was going to be difficult but I was surprised at how simple it was. I got a nice cross hatch pattern down each cylinder but I ended up revealing a few fine vertical scratches. I'm going to take it down to a buddy's tomorrow that does a ton of work on cars, for the past ~10 years, and see what his opinion on the scratches. I tried to get a pic of them but I just couldn't get it to show up. I really hope I don't have to take it to a machine shop but if it happens then so be it. *shrug*
Excellent!! I'll pull apart the top end and blast all that crud off. I was planning of cleaning out each of the ports like I did the intakes to try and smooth out the airway. They are pretty rough on the inside and I'd like to eliminate that. After I get that all cleaned and whatnot, would there be a problem smoothing down the head of each cylinder to an almost polished finish or would that just cause problems? Thanks for all your help!!! I really appreciate it.

Teazer - Thanks for that bit of info. I was curious as to what it meant. As far as I can tell they are all identical. I discovered a small indent on each piston after I cleaned them and I freaked out on the first one thinking that something caused damage but realized that each one had it in the same spot. Any idea as to what that could be for? My thought was that it was for the spark plug but it would only work on one side.


I've been on a blasting spree the past few days and did a full clean/rebuild on my carbs and I think they turned out excellent. Everything is still left in bare aluminum until I can figure out a paint scheme and if I want to polish anything.
Props to Swan for the idea of using the white background.

Blasted the jugs before honing the cylinders

Still have to get the remainder of the old gasket completely off

Completely rebuilt carbs cleaned with an ultrasonic cleaner and then blasted with glass beads

Cleaned up the master cylinder for the front brake

Blasted the oil pan and cleaned up the bolts to a nice shine. It took forever to get all that caked on oil/road grime off before I could blast it.

 

[beachcomber]

Re: Project "Indecisive" '72 CB500 Four

Nice build - sets the bar for my own CB550 project.

BTW - a couple of small points. You can buy a proper "carbon scraper" from most auto tool suppliers - a bit like a blunt chisel. In fact in the 60's that's precicely what we used - a blunt chisel!

Also - most pistons during that period were "sized" to the cylinder bore - not sure if that applies in this case.

 

[WoodsCustoms]

Re: Project "Indecisive" '72 CB500 Four

danish- looks really clean! Nice job on the blasting.
As far as smoothing the ports goes- I am not an expert, but my dad always said that the rough casting marks atomized the fule better. My suggeston is to do your research and ask around...
Regarding the cylinder head- I know you can polish the tops of pistons with aluminum polish to increase flow and reduce carbon build up, guess you can do it on the dome as well? Only done the pistons myself.

If you really want to get crazy have a pro do some head work (valves, porting, etc) as the old honda motors really benifited from this kinda work. Oh, and while your at it put in some cb 750 pistons and sleeves. It's really easy to get carried away...

Can't wait to see how it comes out! I got half CB500 K project sent back up from TX that I had in storage with my dad for years. I'm itching to build another 4...

 

[theboxrules]

Re: Project "Indecisive" '72 CB500 Four

Can you post more pics of your "blast" cabinet? I love the ingenuity there and might like a shot at duplicating it. How is your feed connected to your blast nozzle? Do you have a filter on one side for exhaust air?