I'm working on a 04 450 foreman. I had it bored out with a new piston and rings. It's a Wiseco piston and they didn't tell me they had file-to-fit rings. When I first put it together it had compression but shortly after starting it went dead. After that it only had 60 lbs of compression. I took the engine back apart and found that the top compression ring was butted up with no gap at all. I removed the rings and had them filed with a .014 gap on the top ring and a .017 gap on the second ring and put it back together. It still doesn't have any compression though. Do you guys think the damage was done to the compression ring? The compression is being pumped into the crankcase for sure.

 

If you used the same compression ring, you can't that. You have to start over with a fresh ring package and hone job.

Give the ring lands a VERY hard look. You might have even hosed the brand new piston if you butted the ring packsge.

Rechack ALL clearances also.

 

Thanks. I checked the ring land and they look good. I'll get this thing torn back down and get another ring package coming.

 

O yea, word to the wise. Even if a ring set is not supposed to be file-to-fit you still better check the damn ring gap. This project has turned out to be a nightmare.