1976 Yamaha XS500C restomod

Re: 1976 Yamaha XS500C cafe/ restomod

Oh man I hope I can save some pain when it comes to the XS 500 8 valve ...

.... So running out of replacement heads from Yamaha we were instructed to remove the head and peen the combustion chamber and place a small drill start at the end of the crack on the outside then install the spark plug with an aluminum flat washer and red aviation Hi-tack at some small torque value .
I went looking for the procedure in Yamaha documentation and found none but to this day I find Yamaha service techs from that era that remember something like those instructions .
By the way the crack almost always radiates from the spark plug hole to the exhaust valve seat . If I were to find even a clean enough late model head I'd warm it up and shot peen it to relieve stresses just in case .
There are a few things I'll have to refresh my memory about when it comes to R&R the flywheel and adjust/time the balance chain . It was install a few degrees ahead/behind the keyway and twist into place . I'm sure you get the idea . Basically it sux the first time .

The stock carbs are their own deal . Unlike much of anything you'll see in classic rice .
On most you can dual disc the front but the order of installation is specific and escapes me as it was too many years ago but not long enough to forget how many times I had to back up and start over .
For you and others that resurrect the cast iron single pot caliper the O-ring from one of the 240Z Datsun calipers ( can't be specific here I'm gonna claim senility) is a direct fit . I have no idea what to do about the piston other than have someone carve one from SS .

CHAIN (DK219H-82L)
14410-235-003 (replaces 14410-216-003)

JOINT, CAM CHAIN
14411-216-000

http://hondapeninsula.com/fiche_section_detail.asp?section=120034&category=MOTORCYCLES&make=HONDA&year=1965&fveh=2876

chain just happens to come from a CB160 (cam chain)

Now the balance chain is a Kawasaki part
Kawasaki 92057-1415 (CHAIN,CAM,BF05-104L)or at last check Tsubaki still makes the BF05 in bulk , you just have to find someone that carries it .
Seems a shame to cut 62 links out of 104 and use the rest for a bracelet ...

The later tensioner for the balancer has a thicker slipper for the starter chain and is a better adjuster for the balance chain . Take a good look while the flywheel is off . I have a fair copy of the parts fiche if needed .

If you find a better way of installing the flywheel/starter clutch/chain gears without dropping the key into the ... than I have please share .

Is that enough blathering for now ?

~kop

Re: 1976 Yamaha XS500C cafe/ restomod

Hey, I'm always happy to hear blathering when it comes to one of my projects. I appreciate all the info I can get! I've done quite a bit of reading on this thing myself; I'm hoping that I've got one of the better ones without a cracked head. She seems to run pretty well; is there a telltale sign I should look out for? I'm hoping to get away with adjusting the chains and not a whole lot else. Carbs have already been rebuilt, brakes have been disassembled, cleaned, reassembled, and are working well, though some hoses are needed for safety.

My hope with this thing is to clean her up, get her on the road, and just have a decent cheap scoot with a little character. So far it's going pretty well considering what I started with...

Re: 1976 Yamaha XS500C cafe/ restomod

Dig into the oil filter/adapter modifications , The head issue begins like a tapping similar to the exhaust leak at the head pipe easily mistaken for a valve tic, This is accompanied by a weeping from the spark plug hole , I don't recommend removing and replacing spark plugs when the engine is hot any more than is absolutely necessary . Establish what torque will retain them with a fresh crush washer and a used crush washer and use a torque wrench in all but road side emergency occasions . Begin with manufactures recommended torque and go from there .

I may have service bulletins from that era around here somewhere

~kop

Re: 1976 Yamaha XS500C cafe/ restomod

She needs plugs and the left one needs the threads chased anyways (it got a little tight last time I had it out) so I'll check for weeping when I do that and have a good look at it. I know about the obsolete oil filter business too so I'll be addressing that issue as well. No abnormal ticking for now, so that's a good sign.

Thanks again! I know these things are "quirky", but I enjoy this kind of stuff.

Re: 1976 Yamaha XS500C cafe/ restomod

As of today I've got the front end from the steering head down disassembled, painted, and reassembled with a new front tire. Of course I managed to scratch the crap out of my freshly painted wheel, but it's nothing a little touch up won't cure. Tomorrow I'm off, so there will be lots of cleaning and painting happening. It's nice to see some progress. It helps with motivation...

Re: 1976 Yamaha XS500C cafe/ restomod

Got a lot more painted today, plus a few bits polished. Just working my way back from the front:



I used VHT header paint on the pipes after roughing them up with 220 grit, so hopefully the shit will stick. I'm going to try to follow their directions for curing to the letter. You can't tell real well, but the center fins on the head have the edges polished too.

After these pics were shot I got the rear wheel off and the swingarm painted. New shocks will be ordered tonight. I was going to clean them up and paint them but I managed to break the bent one when I tried to straighten it out.

Re: 1976 Yamaha XS500C cafe/ restomod

I've realized that I probably started this thread in the wrong section, because once it's done it's going to look like a pretty much stock bike with a little bit of tracker inspiration, not a cafe. My bad. :

Re: 1976 Yamaha XS500C cafe/ restomod

fomocoguy said:

I've realized that I probably started this thread in the wrong section, because once it's done it's going to look like a pretty much stock bike with a little bit of tracker inspiration, not a cafe. My bad. :

Click to expand...

PM Tim. He can move the thread wherever you'd like.

Re: 1976 Yamaha XS500C cafe/ restomod

I will. Thanks!

Re: 1976 Yamaha XS500C cafe/ restomod

Moving thread to "Specials" section as requested by OP.

Re: 1976 Yamaha XS500C cafe/ restomod

Looks awesome man. Myself and a fella Joe on here have pretty elaborate build threads on these bikes XS500 and TX500. Check them out and let us know if you need any help. The bike looks good. Sync those carbs and your golden!

Ted

Re: 1976 Yamaha XS500C cafe/ restomod

Thanks! I've looked through your threads and you guys do great work; definetly above and beyond what I'm doing here.

My only question for now is what is with the giant snap ring holding the rear sprocket on? Who at yamaha thought that was a great idea? ;D

Re: 1976 Yamaha XS500C cafe/ restomod

Might have been one of the hold overs from the Hosk/showa/yamaha linage .
Do a little history search to see what brought (relatively) modern four strokes to Yamaha .
Although the 8 valve 500 is but a distant relative of the TX/XS 650 those engineers that followed the Hosk project and came to Yamaha from Showa were on one side of the scale unique and effective but on the other hand were obsequious and somewhat less than clairvoyant . A curious mix of engineering that was Yamaha in the 70's .

~kop

Yeah, one thing that drew me to this bike is the engine and it's "modern" attributes with the dohc and 4 valves per cylinder. I know it has a few drawbacks, but being the later model oval port version helps.

Today I got some more painting done. And cleaning. And painting. And cleaning.

One thing that was fun was I had the opportunity to rebuild my gas cap, which is something I've never done. It was neat to actually tear it apart and see how the vent works and how it's all held together. I get the most enjoyment out of doing new things that I usually wouldn't bother with and learning something new. Couple pics-

Not much of an update, but I got my filters in today. As you other tx/xs 500 guys know, the oil filter was obsolete long ago, and it's oddball (for a motorcycle) 22mm threads make it very difficult to find replacements. People spend 40-50 bucks on oem filters on ebay. After lots of searching I found a thread on a yamaha forum claiming a place called speed and sport was now carrying replacements. I ordered 2 but will order more if this bike ends up in my garage for the long haul. They look like nos aftermarket items, so I'm sure quantities will be limited. Saved me from buying a custom adaptor for now...

Rear wheel installed with new tire, new oil filter in place, and I'm picking up my seat today. Then more cleaning and painting....

painted stuff looks good, are you useing 2K color or "rattle-can"?

Just rattlecan. I've grown to be pretty decent with it over the years, plus it falls within my budget (which has already been expanded). My goal is to have it all done including tires and original purchase price for under $1000, and so far I'm doing well. I'm at about $850 and the only things left to buy are blinkers, mirrors, and a headlight bulb.

Picked up my seat today, so now you can really see where I'm going with this. The rear fender will be cut off and a tail light will be fitted up tight under the cowl (which will be painted to match the rest of the bodywork). I still haven't decided if I'm going to keep the front fender as is, trim it, or delete it totally.

I haven't had a whole lot of time to work on her lately, but I'm slowly picking away at it. I got the headlight bucket painted and installed, along with the new blinkers and tail light. Now I'm working on getting the controls all painted and polished.