1990 60hp johnson

[corvette$dave]

Baffled, 1990 60 hp & up(70hp) use same replacement power head, several of these size motors use same carburator kits so does hp difference come from just a high speed jet change or something else?? Looking to boost my 60 hp up, can it be done cheaply without any major side effects? : thanks

 

[JB]

Re: 1990 60hp johnson

Don't know exactly, Dave, but it sure as heck isn't jets.

More likely in the carbs venturi diameter, profile of the synch cam, exhaust geometry, reeds.

The difference in on the water performance would be trivial and not be worth spending any bux on.