Need help mounting a bracket

[Topflitegraphics]

OK - before I start drilling holes into my nice fresh transom, I want to double check with you guys about how high to mount the bracket.

The bracket I have has a 25" setback and since I bought it used it came with no instructions. After googling it several different ways, I have seen several different heights listed as to where exactly to mount the bracket. Before I start drilling holes I would love to hear some wisdom from those that have done this.

As you can see from the picture, I designed a mounting template. As such, I am pretty sure of where my holes will need to be once I decide on the actual height of the bracket. I currently have the template taped in position at 25" from the keel whcih is one of the heights that I have heard to use. I have measured every corner and she is nice and level but am kind of freaking out about drilling the first hole LOL

[DonV]

Here's how we did the bracket on my brother's 23'er. This is a bit tricky to explain. We measured 29" from the keel to the center of the top engine mounting holes on the bracket. To do this we took a straight 2 x 4 and used a floor jack to hold it against the keel about 3' out the back (there's a little 3-4" wide flat spot to hold it against) and then moved the bracket up and down against the transom until we got to the 29" number squared up from the 2 x 4. His bracket was 27' deep. Once we got that spot to the top of the bracket against the transom we leveled, centered and drilled. I have no idea what that measurement was on the transom, all we cared about was getting the engine mounting holes at 29". If we did it over we would have done 28", his engine is a 25" shaft eTec and his it's bolted on the second hole from the top, only one hole left to move the engine down. This can be done on a large sheet of cardboard to scale using 13 degrees as the transom angle, oh yeah we had the luxury of a forklift.

Oh I forgot.......drilling holes in your transom is fun!!

[Topflitegraphics]

Originally Posted by DonV

Oh I forgot.......drilling holes in your transom is fun!!

Said No One! Ever!!

[beastley]

A lot of variables there. If it was me I’d mount the motor to the bracket, then position the bracket to the transom to figure out the height. Obviously you’d have to have an adequate lift for the motor. Perhaps a local boat shop would help. Just a thought. Good luck!
John

[DonV]

True, but the bottom line is you want your cavitation/AV plate around 4" above the keel at 27" off the transom using a bracket.

[Topflitegraphics]

Originally Posted by beastley

A lot of variables there. If it was me I’d mount the motor to the bracket, then position the bracket to the transom to figure out the height. Obviously you’d have to have an adequate lift for the motor. Perhaps a local boat shop would help. Just a thought. Good luck!
John

That would be great, if I had a motor...

[flyingfrizzle]

I built a jig to hold the bracket in a floor jack so I could raise and lower easily when fitting up the one on my 20. Used a plumbob on the mounting tab and measure down from mounting height to your position you want your av plate. Make sure you pull measurements on the outboard as all 25" motors are not the same length to the av plate. Use a stright edge off the bottom of the boat to determine where the hull bottom is at your set back. Figure in the water rise off of the transom. Get the plumbob and market length of the mounting point of the outboard to the av plate on the string. Set the bottom mark (av plate) of the string of the plumbob at the correct height above the stright edge corrected for water rise and the top mark on the string (outboard mounting point) is where the bracket mounting tab needs to go. Figure it so that your outboard is in the lowest position in the adjustment so you can still raise the outboard as it likely will need to be raised not lowered once water tested in motion. Also don't forget the boat must be sitting on the trailer how it will sit in the water when mocking this up. Guessing the boat angle will be the hard part.

[Topflitegraphics]

OK - Then I will wait until I get a motor to mount the bracket

[bbh57]

Check and double check... in the pictures it appears that the top of the bracket is a 90 degree angle to the bolt on face. ( most bracket built at slight difference. 15 degrees or so.) the transom angle will make it necessary to mount it higher. Curious as to how the motor bolts to bracket. Agree with Don, Cav plate 3 to 4 inches above plane of hull. have mounted my last 2 boats that way. worked fine.

[Xcomunic8d]

Hope this helps. Lots of useful info here.

Good luck!
http://www.dadmarine.com/25sgl.html


Ps. You may want to add aluminum bar stock on the bow side of transom for the bolts to pull up against and spread the load.