TOPIC:

A guy I knew in Fiji back in the 70's had lived for a while in Malawi and had to scrounge parts. He used piston and rings from, IIRC a Buick in his BSA.

Well I'm wondering if anyone has turned up a source for dimensions on engine parts. I have a specific problem, but the data could be useful, especially to folks who are living where parts are hard/impossible to get.

In my case, I acquired a 500CC Honda Thumper engine that's been bored out to 0.080" over. The sleeve looks like it's got enough thickness left but the largest oversize piston available is a 0.060 over. I suspect rings will be pretty easy to find but am havibg a heck of a time locating a substitute piston.

On a related note, has anyone found a real good deal on a shop that does hardwelding? I need to resurface the cam followers too and $65/each x 4 s just not practical on an old bike like this. I can do my own grinding with the surface grinder and a rotary table but can't seem to find anyone who will touch the small rocker arms for hard welding. The automotive machine shops will do a big old camshaft but seem timid to try smething so small.

Also related, how difficult is it to resleeve a cylinder. Maybe I should ask, what's the procedure. It's you typical air cooled Al cylinder.

-Duck

Duck,

Go to www.thumperpage.com/ They should be able to help you with the honda 500 stuff. Most of those big honda singles use interchangeable parts. A few years back, we built a customers GB500 to nearly 700cc using a combination of XL/XR 500, 600, and 650 parts in a GB500 engine. Whit Bros is a good source for what fits what on those too. Good Luck

Tim

Hardwelding,,I haven't heard of that for awhile, If you have a welding/trade school around ? Maybe for free ? If you can do the machine work to finish them.
For the cylinder liners (steel liner/aluminium block)you can do that at home in your oven....but it stinks up the place

if you can locate some spray metal people that would be the best way to build up the cams, the problem then is to get them ground back to specs, you will need to find a good cam grinder to do that job

Thanks.

Cam shaft is missing. I'm scrounging for one from a XL500.
The rockers have pretty thin hardening and it's starting to wear through. These, I can grind.

I have an electric oven in the workshop. Will see if I can get the liner out. Never tried or seen done. Hence my qestions.

-Duck

Look up LA Sleeve on the web. They may be able to help with the liner (piston sleeve). They are the biggest source of aftermarket sleeves I know of and may be able to offer some advice as well. You might want to shoot an email to APE Jay as some of these problems are beyond what is normally being done by a shop due to the restore nature of your project.