2001 YZ250 - Loud Knock

[billtx]

My friend ended up with an "abandoned" 01 YZ250. It sat for a couple years. He cleaned it up and rode it a few times.

Makes a loud knock when riding and when sitting in neutral. Not clatter, just a few knocks on the way up in revs. Does the powervalve on this bike make a noise? I would think if it was the crank/rod it would have blown by now. Not sure what else to think.

 

[christopher in tam]

Romove the top end and inspect it before things get worse. Could be a crank bearing, rod bearing or and hand full of other things.

 

[MikeT]

Sounds like a blown crank to me also.

 

[billtx]

Thanks guys. I guess we need to pull the cylinder and check it out.