powerhead swap??

[samsix6]

hi there folks, before i start could any of you OMC guys tell me if i could swap the powerhead from an 83 evinrude 25hp onto a 75 johnson 20hp?

 

[restornator]

Re: powerhead swap??

different crankshafts that accepts 2 different drive shafts, but that doesn't even matter because it's not the same block. A 1971-1975 18/20 or 25 can replace your powerhead, possibly later depending on the mounting pattern on the exhaust tube and lower engine cover

 

[samsix6]

Re: powerhead swap??

hi restonator thanks for the reply, are you saying that if the mounting pattern is the same it will go? and will i have to use the driveshaft from the 25, or are the driveshafts interchangable (the ev 25 is a short shaft, the johnson 20 is a long)

 

[Chinewalker]

Re: powerhead swap??

The '83 powerhead will not fit the '75 in any way shape or form. Different mounting patterns, different crankshaft splines. The '83 is a 33-cubic inch powerhead and is a completely different animal from the '75. Any of the 22-cubic inch powerheads (18, 20, 25hp) from about 1968 to the end of their run in 1976 should work.