50 hp vs 60 hp 2 cyl differences

[rekcuftar]

I have a 60 hp small 100 block and access to a 50 hp large 100 block. What's the difference between the 50 and 60 hp power head. Is the porting different or just the head? Where does the 10 hp come from and can it be bolted on what is considered the better block or is the block itself different.

[JohnsonM50]

For strictly a parts comparison w/ #'s you can check with BRP parts catalogues The site is a little slow sometimes but will have exploded expandable views & #'s by year & model. Good Luck

[Fastjeff57]

I have a nice 60 hp OMC twin power head suitable for rebuiding. The cylinder walls look good--no scrapes--but the compression was down a bit (110 - 120). Motor ran fine but was "down on power".

Sell the entire powerhead with electric system (has good spark), or just the block and crank assembly, or the block alone. Any takers?


Jeff