TimMillner

I have a tunnel hull. Is there a rule of thumb on approximate motor height mounting. I do not have the plans for the model. It is a dumas hotshot 45 with a k&b 7.5

Hydro Junkie

IIRC, the prop shaft is set with the bottom of the shaft even with the bottom of the sponsons. Been a while since I was around one of those so..................

kevinsburns

You want to make sure you can raise and lower the outboard. Depends what mount your using for the next steps.
Prather mount: Install mount to outboard so the screws are at the half section of the slides, this way the engine will move upward and downward for adjusting height, Now holding the engine with mount hold against the transom so the centerline of the propshaft is level to the bottom of the sponsons. This way the starting point is (Neg) and you can move the engine up and down to find correct prop depth.
Dubro Mount: Mount to engine, hold against transom so the center line of propshaft is level with the sponson bottoms, judge the halfway points of the slide areas, this way you have up and down slides for adjusting prop depth.

Hint, place the engine a wee bit offset 1/16th inch to the right much like "Example" the Aquacraft tunnel, this helps in turns. The Hot Shots do not have this built in with the design of the hull.