How To Pull Main Bearings Off Crankshaft PK80

[2smokebob]

When I split my PK80 case the crank bearings stayed on the crankshaft. Since the bearings are recessed I can't use a regular split bearing puller. I was wondering how they are typically removed. I can get 'em off by welding a piece of pipe to the bearing, but thought I should ask for a smarter way first.

Home shop machinist & previous experience with vintage dirt bike engines......trying to build a good bicycle engine.

 

[crassius]

assuming you plan to use new ones, I use a drift thru the journal hole from the other side to hammer it off - angling the drift, one can just barely catch the outer race

NOTE: some cranks have smaller bearings than others

 

[butre]

I just give them a good ****, they usually come right off

 

[2smokebob]

Thanks for your help! I tried a brass drift pin through the crank pin hole....they wouldn't budge. I ended up welding a piece of 3/4" water pipe to each bearing. Then I used my 9lb slide hammer to pull them off. I held the crank with my left hand & worked the slide hammer with my right hand, vertically. They were really tight, but by pulling them off the way I did (straight) there was no damage to the crank.