How low to go?

[McMudpuddle]

I am replacing a jet motor with a prop motor. After mounting the new motor in the existing holes, it looks as if the prop may not be low enough in the water. The center of the prop is level with the bottom of the boat.
The question is how far under the bottom of the boat should the prop be?
The boat is an Alumawweld intruder with a very slight V in the back, almost flat, the motor is a 1985 Merc 90 horse.

Thanks!

 

[steelespike]

Re: How low to go?

Starting point is with the antivent plate(just above the prop) even with the bottom of the boat.Then raise the motor a hole at a time to a point just before venting becomes a problem.Carefully adjust trim as you go.
Be sure motor is in good tune throttle opening and good prop.As little as an inch can give you 2 or 3 mph.and an improvement in economic performance.

 

[McMudpuddle]

Re: How low to go?

Is the antivent plate the deal the trim tab bolts too? Thanks again

 

[steelespike]

Re: How low to go?

Is the antivent plate the deal the trim tab bolts too? Thanks again

The Plate just above the prop, the trim tab is just below it.If you are refering to a hydrofoil ,sort of a wing attached to the antivent plate,take it off not reccomended.There are better choices.

 

[McMudpuddle]

Re: How low to go?

Thanks a bunch. Took out a filler type jack plate and it looks pretty good.