18hp evinrude

[donnym]

I just purchased a 1971 18 hp Evinrude. I noticed that it is similar to the 20 25 models. Is there any quick and easy steps to boost the power to those levels? Any tips would be appreciated.
thnx

 

[samo_ott]

Re: 18hp evinrude

I have many 18's... A 20 and a 25 all of the 22 cubic inch engine but am not sure off the differences. The block is the same. It's probably the usual differences of carb, exhaust and maybe cylinders... Can it be changed up? Probably. But at what cost...

 

[F_R]

Re: 18hp evinrude

I just purchased a 1971 18 hp Evinrude. I noticed that it is similar to the 20 25 models. Is there any quick and easy steps to boost the power to those levels? Any tips would be appreciated.
thnx

In a word, No. It can be done, but requires different pistons, cylinder head, and carburetor. I think the 25 crankshaft may be different too (balanced). At any rate, it certainly is not quick, easy, nor cheap.