How To Pull Main Bearings Off Crankshaft PK80

Discussion in '2-Stroke Engines' started by 2smokebob, Jul 20, 2015.

  1. 2smokebob

    2smokebob New Member

    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.
     

  2. crassius

    crassius Well-Known Member

    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
     
    2smokebob likes this.
  3. butre

    butre Well-Known Member

    I just give them a good ****, they usually come right off
     
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  4. 2smokebob

    2smokebob New Member

    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.
     
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