Search the Community
Showing results for tags 'port'.
Hello all! Long time lurker here, great site! Long story short, I pick up a bike with low compression for a little project. I notice "FMF" on the side of the cylinder ask him if he knows anything about it? He replies "the guy I got it from said it was an FMF race bike, but I don't think so. Figured someone just carved that in the side." I have never had my other yz250 apart, looking at the ports and comparing them to the few pictures I have found, it does not seem the cylinder was ported. Admittedly, I very inexperienced when it comes to any 2 stroke porting. Stock rebuilds is how I have always rolled. Also, I noticed the "c12 only" but the head only looks lightly milled, if at all. Any expert eyes out that have some input? I am trying to keep this rebuild reasonable since the holidays are around the corner. There is a gouge in the cylinder from the ring breaking. Last time i sent a cylinder off for repair it was 350ish. If it is a stock cylinder I may try to find a used one in good shape a little cheaper. Any help or suggestions would be great appreciated!
Bike is up-jetted to correct jetting, air filter is fairly clean, bike has only got 1200 miles since its most recent top end rebuild recommended is every 6000 miles on this 125 2 stroke road bike, top end was done at garage, always warmed up and ridden nicely. seems to have deep to severe scratches on the piston and cylinder bit, seems to be where the exhaust port is and on that general side. could do with some help on understanding the possible issue so i can stop it from happening again.