thats what i figured..if it had a burnt valve it would have low compression right?,only thing i havnt really tryed yet with the carb is measuring the fuel level in the bowl not too sure on how to do that but wen go to drain the carbs it doese have quite a bit in them.i did try a other cdi that i had but it had started smokin and then lil pop and put hole out back of it didnt even have the key turned on or nothing was in a other bike that had put out spark but didnt have it runnin were bike was blown and didnt blow the cdi unit like it did wen i pluged it in to the bike i have now,wen it blew the other cdi i had put my other one the one that came with the bike i have now back on and didnt seem to blow it up like it did to the other one,not too sure what would have happend there,dont wanna buy a new cdi unit and plug it in and it fry it like the last one if i do end buyin a new one to see if thats what it is,ive tryed for hours adjusting the carbs and it seems to run best at about 5 turns each or so,all stock jets and have the needle set at third clip.