how long should the shaft be?

[bailnutzHUNTER]

I have 1974 14' yarcraft(tri-hull) that had a 1974 35hp chrysler on the back(motor was bad). So I I used a buddy's 1978 35hp(what I thought was a long shaft) Johnson but it never got the boat on plane. It seemed as though the shaft was to short but it still pumped water well. When I tried turing the motor just loses power. The chrysler motor sat about 5 in deeper than the johnson. So the is the shaft to short? The boat is rated up to a sixty horse but only weighs about 500lb so it is light. How far down should the prop be below the hull? Right now the middle of the prop is even with th bottom of the hull. Is that to short?

 

[Lion hunter]

Re: how long should the shaft be?

Yes that is to short. The caviattion plate should be about even with the keel. Measure the transom from the top to the bottom of the keel. This will tell you the length of shaft you need. Measure vertically and not along the transom. For the motor you measure from the top inside of the transom bracket to the caviatation plate.