yfz 450 problems

[oglejust]

a friend of mine has a 2007 yfz 450 that he bought new and has never been in the engine, he was riding it and all of a sudden it locked up, but it will start and run for a bit then it locks up again. we pulled the valve cover off and got it at tdc, i noticed that the exhaust cam is 1 tooth off clockwise, i realize that its the same as the cam mod but he didnt do it and he bought it new... seems weird. it turns over fine with no plug in it, any ideas?

[2fun]

Originally Posted by oglejust

a friend of mine has a 2007 yfz 450 that he bought new and has never been in the engine, he was riding it and all of a sudden it locked up, but it will start and run for a bit then it locks up again. we pulled the valve cover off and got it at tdc, i noticed that the exhaust cam is 1 tooth off clockwise, i realize that its the same as the cam mod but he didnt do it and he bought it new... seems weird. it turns over fine with no plug in it, any ideas?

Sounds somewhat strange to me. I suppose it is possible that the cam chain was loose enough to allow the cam to skip a tooth, but seems kinda unlikely if he bought it new and has never been into the motor. Esp on a 2007....

[oglejust]

yeah but ppl have the timing like that all the time, that still doesnt tell me why it'll start for a few sec then lock up

[AJ_YFZ]

Have you checked the valves?

[anadke87]

Originally Posted by oglejust

a friend of mine has a 2007 yfz 450 that he bought new and has never been in the engine, he was riding it and all of a sudden it locked up, but it will start and run for a bit then it locks up again. we pulled the valve cover off and got it at tdc, i noticed that the exhaust cam is 1 tooth off clockwise, i realize that its the same as the cam mod but he didnt do it and he bought it new... seems weird. it turns over fine with no plug in it, any ideas?

same thing happened to mine i have an 04 and the problem was that the crank bearing actually siezed up ity would strat and run fine until it got hot enough it would expand and sieze up

[oglejust]

well we got the engine off sunday and it turns out its the rod bearing... gonna be an expensive fix