motor position on transom

[Zaxxon II]

I didn't get any answer on the Force motor forum so I'll try here. I have a 50hp Force on a 15 1/2' Maxum bassboat. I don't have a tach or trim and the boat will just barely make 25mph. Where is it better to lock the engine, in the bottom hole (next to transom or out further. What will these various adjustments do. It makes sense that trimmed all the way out from the transom should increase the hole shot, and all the way in would help on top end. Any comments?

 

[TwoBallScrewBall]

Re: motor position on transom

Basically... as far out as you can while still maintaining respectable (acceptable to you) planing time and no cavitation (slipping) from the propeller.<br /><br />Further out will actually decrease holeshot, while increasing top end since it will push the transom down and bow up putting more of the boat out of the water. Further in does the opposite.

 

[quantumleap]

Re: motor position on transom

You'll have to experiment by going out as far as you can without having excessive bow rise while getting on plane. The addition of a planing aid such as trim tabs or a hydrofoil may help your situation quite a bit as it would allow you to maximize top end by having the motor trimmed up a little higher and still planing well. The problem with using a foil with no power trim is that you want it to run parallel to the water while underway, and that limits the amount of trim you can effectively use. Do a search on tabs and hydrofoils.

 

[Zaxxon II]

Re: motor position on transom

I have an extended plastic device attached to the cavitation plate at the bottom of the motor. Is this a trim tab or hydrofoil?

 

[quantumleap]

Re: motor position on transom

That's a hydrofoil. You might want to take a few test runs at different motor heights with and without the foil.