Get rid of the side to side slop that is present on the wrist pin and needle bearing. This will reduce vibration, increase the life of the needle bearing, and allow higher RPMs. trying to find the right materials to use and trying to find the right size was a challenge. Didnt want to buy anything so what I did was took an old piston that was laying around. i took snipps and broke the transfer sides of the piston off exposing the inside of the piston.
View attachment 186153 I then got a blade from a hack saw and by hand gently and evenly cut 1/8th inch off of both side of the wrist pin sleeve inside the piston.
View attachment 186154 This will make two 1/8th inch washers that will fit perfectly on your wrist pin. 1/8 is the perfect size to keep the needle bearing centered with no slop. If the needle bearing doesnt move easily when you roll your finger across it. Then its to tight and you will have to file or sand some material off your washers.
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When installing the washers put the cut side touching the bearing. This DIY is free and works perfectly for this application. Not including tear down and rebuild. It only took me 1hr to accomplish this. This is how good they fit.
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LIKE I SAID MAKE SURE THE WHOLE BEARING CAGE AND NOT JUST THE NEEDLES CAN EASILY ROTATE AROUND THE WRIST PIN. REBUILD THEN HOLD IT WIDE OPEN.