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Old 01-21-2015, 10:20 PM
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Davezilla Davezilla is offline
Motorized Bicycle Elite Member
Join Date: Mar 2014
Location: San Antonio Texas
Posts: 2,710
Default Re: what did you do to your motorized bicycle today?

What I was planning on doing was to try and find some brass washers that would slip over the crank that were like. 040" to. 050" thick to limit the side play to. 040" or .020" crank to bearing clearance on each side but any washer that would fit would also block off the fuel/oil mix from reaching the bearings so it was back to the drawing board and I need to make a mandrel that's the same diameter as the crank and then punch some small pieces of sheet brass in the right thickness then cut it so the outer diameter is the same as the bearing's inner race. That would eliminate the slop in the crank but also leave about .020" side play to keep it from going too tight after the engine is fully warmed up. I'm not sure how much the crank and all expands from heat fully warmed up compared to cold, but at .020" there should be plenty enough room but drastically reducing the side play. This side play as you saw can cut into the case, ruin the seals, or even short out the mag if enough tiny shavings are in there floating around when the engine is running which would just feel like a hickup or a small miss every now and then, but could eventually ruin a mag by shorting it out on and off while riding.
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