I have a small problem, my son's 300 has jumped time, chain & tensioner seems fine. It actually ran well, except at higher rpms, it cut out. It has been doin this for a while now, I went thru the carb, ignition, & every thing else I could think of. I finally removed the top cover, & put it on "T", & the chain gear is off about 1 tooth. I am thinking that maybe the chain has been replaced before I got it, & installed this way. My question is, how do I get it back in time without removing the clutch cover. I am hoping I can change it on the top, but I have studied it & just don't see a way of doin it without removing the whole chain. Any help with this matter will be appreciated.

 

You can do it from the top. Removing the cam chain tensioner and unbolting the camshaft sprocket will give you plenty 'o slack. Keep in mind it is an automatic tensioner and when you remove it from the cylinder it will fully extend itself. You must retract it to reinstall. Do this by removing the bolt in the back of it (I usually break it lose while still bolted to the cylinder), and turning the small flat blade inside clockwise, you will see the plunger backing off. Hold it backed off until you get it bolted back on the cylinder.

 

Thanks for the help