[e28]

Will the electric start from a 1958 20HP fit the 1954 25HP Big Twin motor?

[F_R]

The bracket certainly won't. As for the starter motor itself, I don't think so, but haven't tried. The '54 was a 6 volt starter and the '58 is 12 volts. Physical size is different as I remember.

[Chinewalker]

What is the 1958? There was no 20hp in 1958. Either the year or the horsepower is incorrect...
- Scott