How to make adjustable transom for Sidewinder 15S and Merc 15

[Smiley]

What is a good solution to make an adjustable transom board to raise and lower the motor and move the motor forward and aftward with about a 3-4 inch movement?

Problem. I have many AX and A wheels to test on a 15S sidewinder and Merc 15 for AX and A class runabout and hydro. The Merc needs to be about 1 1/4 inch higher than the OMC and the sidewinder is lower than the OMC. Also the foot on the sidewinder is about 2 inches forward of the OMC setup with respect to the aft plane edge of the bottom.

I assume you get more dig the farther back the prop is WRT the boat bottom aft edge thus easier to plane and may provide more stability down the straights and more dig in the corners.

What is your experience with this trim feature and also what are the best solutions to the adjustable feature.

I plan to build a hemp hydro this winter.

Bob Smiley

[John Schubert]

Adjustable transom

What is a good solution to make an adjustable transom board to raise and lower the motor and move the motor forward and aftward with about a 3-4 inch movement?

Problem. I have many AX and A wheels to test on a 15S sidewinder and Merc 15 for AX and A class runabout and hydro. The Merc needs to be about 1 1/4 inch higher than the OMC and the sidewinder is lower than the OMC. Also the foot on the sidewinder is about 2 inches forward of the OMC setup with respect to the aft plane edge of the bottom.

I assume you get more dig the farther back the prop is WRT the boat bottom aft edge thus easier to plane and may provide more stability down the straights and more dig in the corners.

What is your experience with this trim feature and also what are the best solutions to the adjustable feature.

I plan to build a hemp hydro this winter.

Bob Smiley

Ask Sam to make the pieces for you. He's an expert at doing such trick things & it will be right from the start.

[csh2z]

I would think it could be done with two different motor boards, each with a clamp bracket assembly on them. Sam should be able to work that out.

[Matt Dagostino]

The Stillwill

George has done this several times.............the Merc 15 to OMC 15 is easy.

The Sidewinder is a different story, but it can be done.

Also Dave Bennett has converted transoms in like fashion.............call them.

Enjoy

[John Schubert]

Transoms

I would think it could be done with two different motor boards, each with a clamp bracket assembly on them. Sam should be able to work that out.

Didn't think of that John, as I thought that he wanted to do multiple test with different settings until the optimum setting was achieved. Although he still could do it that way. Dave & I did that with clamps & angle aluminum what we started the J hydro class to change between his KG4 & my ex wife's Super 5.

[johnsonm50]

Didn't think of that John, as I thought that he wanted to do multiple test with different settings until the optimum setting was achieved. Although he still could do it that way. Dave & I did that with clamps & angle aluminum what we started the J hydro class to change between his KG4 & my ex wife's Super 5.

I've seen it done with a 1/4 inner transom [to seal out water] then a drop in transom position for the motor. Different heights &/or setbacks can be changed out in no time w/o leak concerns.

[Smiley]

Lee Tietze mentioned a 3/8 inner transom (water seal board tipped forward from the rear transom bottom on the plans, tip it forward so the motor clamps clear.) Then add a 3/4 x 1 1/2 brace on the top front side of that board to stiffen it. Then extend the sides aft, reinforced of course then construct the motor boards. I would like to have infinite adjustments and tinker with aft positions, motor tilt, etc and test for stability etc. Does anybody have a good sketch to solve that question?
Bob