I picked this Engine up off of ebay about a year and a half ago. Was able to get the seller to come down on the price a little closer to what I wanted to pay for it. I believe this has an 87-88 CR500 cylinder, it was re sleeved at some time as it is currently on the original bore. Has ATV racing on the cylinder and intake. The exhaust bridge is gone and it was running a Mossbargar reed setup. I sent it off to CW racing to have him go through it. He recommended honing the cylinder and going with a ProX piston and rings. The intake manifold had damage at the edges where the reeds closed on so added a V Force reed setup in its place. The lower end was good to go. I went with a MSV exhaust manifold, these guys are big into the CR500 world and the O rings should help with sealing. I was able to pick up a pipe from Neal at ATV racing (or whatever they are called now, there web site has been down for quite awhile), Keihin carb I picked up quite awhile ago from someone who had pulled it off of a 500 build. So some odds and ends left to get and it will be ready to drop in the Pilot or hopefully one of the EEE's. Here are some pics

More pictures

And some more

Hey Bob keep a very close eye on that comet clutch.
My brothers machine is just a ported and piped 350 and he has twisted off two comets.
That 500 is going to be monster so I would watch for a twisted off stem.
What happens is the stem twists off the fixed clutch face. Then the only thing holding it on the crank is the bolt.
I would check it after every ride.
Grab the movable shiv and see if it wiggles. If it does then it's twisted off.
That's a real nice Engine and pipe. Love it.
CO