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View Full Version : Pressed crankshafts anyone ever rebuilt one? 1cyl, 2cyl, 3cyl?



gazza2006au
13-03-2018, 12:26 PM
My 3 cylinder crank needs a full rebuild just wondering if anyone has ever rebuilt there own pressed crankshaft? the last one i got done for a 25hp Yamaha cost like $350 to press apart clean and reassemble

i am pretty keen to try my luck at rebuilding a pressed crank multi cylinder, i am confident i can get the rods each 120 degree that is not a worry and clearance should be easy enough the only thing i am questioning is the truing of a 3 cylinder crank

i understand u need a BFH ;D i can pop the crank back into the cases for clearance check and alignment of bearing pins

i think a 2 cylinder would be a piece of piss but how much harder is a 3 cylinder?

Noelm
13-03-2018, 01:22 PM
Not too sure it would be any harder doing a 3 cylinder, none are easy without the proper equipment, when they are done, getting them 100% aligned would be possible, but they are also balanced, I don't think a home mechanic could rebalance one.

gazza2006au
13-03-2018, 02:41 PM
Noel do u mean balanced as in drilled with holes?

Noelm
13-03-2018, 07:18 PM
Sometimes they drill a bit, sometimes just a grind, depends on how much needs to be done, I have done lots of Victa mower cranks, they are a breeze to do.

gazza2006au
14-03-2018, 04:25 PM
Going to try build a 50 ton hydraulic press should be fun, if I successfully make a working press it'll save me taking the 25hp yamaha crank back to the shop

Will see how I go picing up the press making material tomorrow