So bought a broken CR500 off the board. Seller claimed it needed a top end. Mechanic tells me looks like the air filter was never oiled/cleaned and there is a trail of sand into the carb. Piston is beat to hell. He opens the bottom end and he says junk everywhere. He then proceeds to tell me that they can't find any aftermarket cranks and Honda wants $4xx for a crank!

So! Any of you two smoker guys have any resource for an '87 CR500 crank? Do you know if any other model year crank will fit?

Thanks!



<----- wife not going to be happy about that cheap dune bike I just bought

I think your best bet is to find a crank/used motor off of ebay and hope the crank is in good shape. Craigslist parts out bikes sometimes also. There are also some salvage shops but they charge a premium for their parts. Sorry I didn't have better info for you man.

That's the road I'm heading down. It's hard to find good information on these bikes. I found an '88 crank on ebay for $99 - looks like it's in decent shape, no? Seems like a good price, too. Thinking I'll just buy that and hope for the best.

Thanks

Maybe try servicehonda.com and their oem parts lookup service? You should be able to tell which part numbers fits which years.

ur stocker cannot be rebuilt? hard to believe my freind, Id ask your mechanic to pull the crank out and ship it to crankworks.

brand new complete crank from honda is 281 bucks at thumpertalk.com

Anyone seen a piston look like this before? What would cause that sort of gouging?

As far as rebuilding the crank - I had no idea it was even done... I sent an email to crankworks so we'll see what they say.

In the meantime I picked up a good crank off ebay for 100 bucks (forgot that TT is doing OEM stuff now). So, if I can get the busted crank rebuilt I'll have a spare one or I can just resell and get my money back.

Thanks for all the help.

Can you post pics of the plug, a closer shot of the piston crown, and a close up of one of the skirts?

is there any peices of ring missing? or skirts? something hard was above the piston, your head should be a complete match to the gouges on the piston

I think with any aftermarket piston or a bored cylinder they have to do work on the exhaust bridge in some cases.

Looks like whatever failed on the crank found it's way up a transfer port to the top of the piston before it stopped rotating. Check inside the pipe for the remains.

if the rings are all still there and the skirts are in tact its something from the bottom end.

And yes the relief for the exhaust bridge has to be added to the jug on the hone or anytime you bore that cylinder. If you do not relieve the bridge it will swell and will hot sieze the bike if your lucky.. if your not lucky you will be holding another ashtray in your hand before long.

My recommendation for port work and or mill work is glenn at gss raceporting out in palmdale he is the 500 cylinder genius and will insure you dont get a stopsign hone job and that everything is milled proper and square!