Re: OMC 25 hp displacement change

[DAN ANDERSON]

The 1976 25hp was not the 32 cu in powerhead. That didn’t come on the 25 till 1977. The 35 came in 1976. Can be a little confusing. 1969 was the first year for the 25hp and the pistons, crank, head, & other things were all different. OMC has a tendency to build motors in families of engines (as most companies). The same engine powerhead is used with different carbs, heads, etc. to build different horsepower. Sometimes interesting things have to be done to hold the horses down or boost them up to meet the requirements. Usually the more horses you get from the same cubes the more fragile the motor becomes.

Dan in TN