Back woods main bearing install

I believe I may have made a huge mistake in the way I just installed my main bearings.  I used heat but apparently not enough, ended up pounding on them quite a bit on the outter race with a brass slug and hammer.  I was working next to a guy who was working on his motor, builds many motors for mx, flat track.. saying thats what he does, so I got generous with the hammer.  Everything seems fine bearing still look and feel healthy, kinda worried about Truness of the bearing as I didnt bottom them out either.  Its an 03 CR250 and my first case split, ive got the rest of the motor back to new OEM everything so i really dont want to waste it. How bad did i just F*** myself?

Some blokes here will insist you've stuffed it.

IMO as long as it was driver from the outer race, no deformation due to brass drift, and it spins true, should be fine. Worst case scenario is reduced bearing life.

Ideally you would use the freeze bearing heat case method. Some bearings have to be pressed in anyway. Its a fact of life

I have always had good luck with just freezing the bearings over night and they drop right in with just a bit of a pop with a rubber mallet or wood block. 

have to agree with above, just for safety you can pull the stator cover and check for play every 15 or so hours.


and as above next time freeze the bearing and heat the case.

Thanks guys, helped to put my mind at ease. I did try the heat differential method but didn't go to the temps I needed to for it to work properly, guy I was working with said to just pound them in with a brass slug had for putting bearings in.  I'm pretty timid when it come to heating Al blocks.  Got the cases back together and the crank feels real smooth so I feel pretty good about it.

It's fine but the bearing needs to be bottomed against it's seat.

easiest way to heat the cases is to make sure they are clean of all oils and stick them in the oven at about 180 degrees(make sure the wife is not

also put the bearings in the freezer the night before, a few light taps should be all that's needed after that.

Just wanted to follow up on the engine build as its the end of the summer.  30 racing hours (MX, harescrambles, and 1 enduro) on it and its solid as could be no oil leaking behind the flywheel, with fly wheel weight 8oz gets great traction and pulls really well.  I don't care to pound my bearings in again but I don't think any harm was done.

Bearings are designed to be driven in like that.

That bearing race is a hell of a lot tougher than that brass hammer

I was more worried about the cases, bearing rotational axis getting off angle.

What works really good, specially removal of bearings.....a hot plate.

Get a cheap or used hot plate place the case half on it, let it heat up for 20 30 minutes.

some bearings will just fall out, others, some light tapping.

Reinstalling I also freeze them for 3 to 4 hours...if line them up right some get sucked right in place.

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