yamyfz450

I use amsoil 10-40. but i am gettin it rebuilt because the previous owner put a crank bearing in backwards and it blew a week ago. but my macanic highly recomends it says he uses it in his yam 426 and never had a problem..

found out the problem the crank shaft bearings went out and the gears where rubbing on the side of the engine case. its gonna coat bout 600 bucks with a new piston rings, and bearings.

it sounds like it is coming from the front or left side of the motor. it makes the noise when it is idling. i shut it off as soon as i herd it so it doesn't mess it up even more. I read up on the tensions should i put a manual one in?

I just bout a used 04 Yfz 450. I took it to a local shop to have them check it out the replaced the cam chain. Got it back oil plug come out wile i was riding so i shut it off. it still had some oil in it took it to the shop the gave me a new plug and oil for free. went back to riding it no it has a loud clinging noise coming from the motor. Any suggestions?