1987, 350 Warrior- when hot seems to stall and has a engine knock, pulled out oil filter and has aluminum chunks in the filter. Were do i go? seems to start and run well untill the bike gets hot, then its very hard starting, it cranks over and seems out of time (sounds like its hitting the valves even) Just bought the bike someone put a Web Cam, R/D valve springs, and a Super Trapp IDS2 pipe. I would like to tear it down. Any advice would be greatly apprecated. I have NOT bought a manual yet, is there anything on the internet i could use?

 

Are you sure the mixture isn't lean, or a high compression piston isn't in there? You may be experiencing pinging from too low octane gas with the piston that's in there. I wouldn't think the person would of left the piston stock when they tore apart the motor. A lean mixture may cause some overheating, but you would probably hear some popping from it. It's pretty common to see aluminum in the filter, so unless it's unbelievably caked don't worry about it. To keep your engine a little cooler look at the modifications part or bluetrax's page on the web. That will show you how to get a oil cooler going, which would be highly recommended for air cooled engines that have been modified. Before doing anything you should definately get the thick book from yamaha or clymer.