Evinrude gurus, advise sought

SMM77

Cadet
Joined
Aug 22, 2010
Messages
9
1977 115HP

Broke crank. Prob cause rod bearing failure. Visual heat indications.

Options?

Are cranks that hard to find?

What would be the best dimensional reference for this motor? Rebuild spec book?

All machining will be done on a 20HP CNC.

Is the powerhead mounting pattern on the exhaust housing adapter compatable with any other series motors?

TIA

Mike
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Evinrude gurus, advise sought

You should be able to come up with a good used crank which will work for you. Must be tons of these cranks around in marine salvage yards. You should be able to use V4 cranks 1974 up through 78. You'll want to replace any rods that are overheated on the crank journal surface. The powerhead mountings/blocks changed beginning in 1977 when the blocks went from single to dual thermostats. That changed the midsection exhaust adapter and the base of the block.
 
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