Jump to content

How to tell if bearings are good/ bad?

Recommended Posts

Hi I'm currently rebuilding a '01 yz250f (rebuilt crank, new connecting rod, new piston and rings), I got the cases apart and I'm wondering if I should worry about replacing some of the bearings in the case, I know main bearings are common to replace and because when I pulled the crank out it pretty much just fell out, no force was needed, so I'm curious if there is a way to check the bearings to see if they are good or not.

Share this post


Link to post
Share on other sites

It is never a bad idea to replace them.  The countershaft bearing is never reused in my case,  and very seldom is the bearing behind the clutch.  those little bearings that the small end of the trans shafts go on don't get too much of a load on them,  but they are so cheap.   I guess you can see I lean on replacing all of them.   

  • Like 1

Share this post


Link to post
Share on other sites

Clean all the gunk out, then spin them and see if they're "crispy" or "crunchy". 

 

Know what a new brg feels like; when an old brg doesn't feel like that it's time to replace it. 

Replaced a crank bearing last year because I didn't like the way it felt.  I don't know that I'd just go replacing all of them "just because".

While they're not terribly expensive (Crank brg was about $75 for just the one), all of them adds up to a fairly good portion of a parts order.

IMG_20160611_203250996_HDR-L.jpg

  • Like 1

Share this post


Link to post
Share on other sites

Yes the first thing I do is have a good look then see how they feel BEFORE cleaning.

And yes crank bearing can be expensive but I got to the point where I had the cases apart on say a bike from 2001 even if they felt OK, I would still replace them for piece of mind.

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:


×