Originally Posted by Kletus
Could have been a bad crankshaft oil seal. This will cause a super lean mixture due to air being partially sucked in through the bad seal instead of the carburetor thus leaning out the mixture. I've repaired several 2 stroke motorcycles that befell this fate. The best thing to do if you have a means to do it is to have the bottom end pressure/vacuum tested. It also could have a splitline seal failure or a crack in the crankcase. A quick and dirty way to check for a bad oil seal is to spray starting fluid around the seal area, if your engine picks up a lot of RPM you probably have a bad oil seal.
i just ordered a new motor for 130 bucks problem solved.