Jump to content
Sign in to follow this  

crank bearing seized

Recommended Posts

hi, iv just restored my yz250 engine, put it through 3 heat cycles just on its stand in nutral. i took it out yesterday and the back wheel locked up 5 min into the ride. i thort piston was seized turns out to be the clutch side main bearing has seized. its got a bluish colour to it like when chrome exhaust headers go blue. the bearing was brand new what could of gone wrong for this to happen. lack of oil is what springs to mind but i mix 32.1 ratio. can anyone help??

Share this post


Link to post
Share on other sites

Sorry to hear that. I think there is an oil passageway for the fuel mix to get down to the bearing from the top of the case is that correct? Could that be clogged?

Only other thing I can think of is a defective bearing, or crank is not running true.

Share this post


Link to post
Share on other sites

the passage way is clear. im putting a new bearing in, if it happens agen i know the crank is shot. its a 1995 so i will have to get a second hand one if im gettin another crank. dont think anyone makes a new crank for my bike.

Share this post


Link to post
Share on other sites

It doesn't mean the crank is shot. It might just need to be adjusted so that the left and right shafts are aligned to a common centerline. A machine shop can do this.

Share this post


Link to post
Share on other sites

My only guess is the crank is terribly out of true...loading the bearing tremendously...

Even so that's an odd failure none the least.

Any chance you can have it checked for trueness?

Share this post


Link to post
Share on other sites

could be. but my old mains were ok just changed them for new.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...