My friend has an 03 Raptor, w/ no mods. It recently started burnin a little oil, and evidently got real low on oil. Now, it won't turn over when it gets to a certain spot. When the exhaust valves start to go down, it gets stuck. Has it jumped time??

 

my friend had the cam chain tensiner fail on his and the cam chain got realy lose and it skipped timeing and the valves kept hitting the piston so it wouldnt turn over and it made a mess of his motor so it sounds about the same as whet your describing

 

rings were probly bad and bured up the piston

 

How do I tell if that's the problem?

Well, I turns over fine until it gets to that.

 

the only thing i can think off is to take it apart thats aout the only way u could tell un less some one else can think of a better way.

 

If this quad were mine, I'd....

Pull the spark plug. Pull the flywheel nut access cover and put a 19 mm socket on the flywheel and turn it over by hand...it should be smooth. If it is locking up then it possibly skipped a tooth..or broke a piston. (Raptor's break piston skirts if they run out of oil...but it would clatter when running) If you think it skipped a tooth, check the timing chain tensioner by pulling it out. It should extend oneway freely but not the other unless you push the release. If this is working properly, then it is doubtful that it skipped a tooth.

To be sure, you'll could pull the valve cover and check to see if the timing marks are lined up...then go down from there.