Convert 1977 55hp Evinrude to a 60hp?

[HansAA]

I wonder if it is possible to convert this one to a 60hp by replacing the carb or swap in bigger jets? Can I use carbs from johnson as well? Hmmm.

Just bought an engine of which the previous owner told me it did not idle correctly. If Im lucky its only the carbs. Bad luck -> compression is bad. Gonna buy a carburetor repair kit, and am unsure whether I should buy the 60hp or not.

Does anyone know the difference between the 55773D and the 55772D? I tried to decrypt by using the "Model Number Designation", but it only goes from 1980 and up...

 

[Chinewalker]

Re: Convert 1977 55hp Evinrude to a 60hp?

I believe one is the standard (15-inch) and the other is the long shaft (20-inch) lower.

As far as changing to a 60, not likely, as they fussed with porting, etc. between 1977 and the 1980s era 60hp twins... You'd be redoing the choke system, too, as the 60 used the primer system, whereas your 55 uses the choke plates...

 

[HansAA]

Re: Convert 1977 55hp Evinrude to a 60hp?

Ok, well now I have to find some other carb/carbs anyway. I screwed up and broke the main nozzle on one of the original carbs today. Have been working on mikuni carburators before, and their nozzles are always possible to replace... Just wanted to dismantle everything to boil the metal parts in citric acid.

Which 55/60hp carburetors can I swap in? I dont mind going from choke valves to prime choke. Is this a mechanical or electric system?