Glad you found a solution that works for you. But for water cooled engines, the anti ventilation plate should be at or slightly below the bottom of the transom to ensure water flows properly into the water inlet, typically located on the underside of the plate or just below it. Those that raise transom as high as you've shown, above the bottom of boat, should be careful to ensure water continues to flow through the cooling water check port (small stream of warm water exiting above-water from rear of engine). Of course, your air-cooled engine won't have this issue. My Sport Boat planes well with a 1965 5HP Johnson; I just add 10#-15# of extra weight on the floor near the bow to help bring front end down into proper plane when I don't carry a passenger.

When that little boat is loaded with Decoys Dogs and coffee that prop will be just fine! I did the same thing with my 6 Hp Johnny. That will work great for his intended purpose! That’s the key... intended purpose! Great job!

this is the smartest way I have seen so far. I have seen many ideas. Yours is the best. Neat and effective.Bravo!

Great idea! I have a long-shaft 9.9 hp Johnson OB that I want to use on my old 1965 Smokercraft 12-ft boat and this simple idea should help me do this. Thanks! I'll make sure that the anti-ventilation plate is below the lowest part of the transom to ensure that I do have proper cooling.

@OldGuyDIY

Жыл бұрын

Thanks for commenting. I am glad you liked the video.

That's a great idea. I have a long shaft motor and I was wondering how to raise it. I like your method.

nice grumman sport boat :D

That's a good idea, as the SportBoat transom is very low, even for a 15" (short shaft) motor. I would say though, that the SportBoat IS designed to plane. Mine will do 12knts solo with a 7.5 hp Evinrude, if I sit in the middle seat and use a tiller extension. It will still plane at 10knts with same motor and two adults in the forward and rear seats.

Cool tip. I subscribed to keep up

Thank you for not showing a video of drilling 12 holes. Nice design.

Good work sir! Is it a good rule of thumb that the prop should be below the bottom of the stern 6"? Thats what it sounded like. From top to bottom my little 12' boat's stern is only about 16" just looking for optimum performance out of my long shaft Merc. Thanks!

This is what I needed. Thanks

@OldGuyDIY

2 жыл бұрын

I am glad the video helped you. Thank you for commenting.

When you got it on the water and opened it up I bet the prop blew out? The anti ventilation(cavitation) plate should be even with the bottom of your transom. looks like it would suck a lot of air down.

@OldGuyDIY

8 жыл бұрын

This modification is not intended for open water. It allowed me to motor through swamps and flooded fields where the motor would have been dragging bottom if it had not been lifted.

do you think with a little more enforcement and a little lower I could make similar too this for a 25hp long shaft motor?

@OldGuyDIY

5 жыл бұрын

Yes.

Awesome

cool video. looking to do something similar for my canoe. did you notice any performance differences with the riser installed

@OldGuyDIY

8 жыл бұрын

Yes, the 6" riser is too high to allow the motor to work effectively at mid to high speed. I cut it down to 1.5" to allow me to use it for running the channel while still allowing me to motor through shallow water that I historically walked through.

@markmello1366

6 жыл бұрын

OldGuyDIY ...so, im sorry, do you mean to say that the total rise equals 1.5 inches now? Or that you lowered it 1.5 inches from the 6 inches, so now roughly 4.5 inches? Im trying to mount my long shaft onto my dinghy soon and this looks good

@OldGuyDIY

5 жыл бұрын

I settled on 2" total rise. I decided to get out and walk when the water is 6" deep rather than motoring through it. Using the angle aluminum brackets it is easy to pick a height, try it out and then add or remove material to find the right height for your boat.

that outboard sits way too high

Hoping for a payoff video! Please post some footage of the boat on the water. Maybe even narrate the modifications from your previous videos?

@OldGuyDIY

4 жыл бұрын

Hi, Thanks for the comment. I sold this boat and motor some time ago so there will not be a follow-up video with this rig. I found that raising the transom about 2", so the anti-cavitation is approximately the same level as the bottom of the boat was the best compromise for motoring at speed and running in shallow water.

What did u use for the support bracket

@OldGuyDIY

2 жыл бұрын

1 1/2" aluminum angle aluminum and 3/4" plywood.

@sethclement7163

2 жыл бұрын

@@OldGuyDIY I'm sorry should have clarified I meant those poles that you run to the boat to the bracket you made

@OldGuyDIY

2 жыл бұрын

The supports are made with 1/2" EMT conduit, cut to length, with the ends hammered down for easier drilling and mounting.

Those engines still need water pumped up to cool the exhaust, looks like you will NOT pump much water.....if any. Don't know how much paint you will have left on your leg.

@manko330

5 жыл бұрын

perfect for the job.

@OldGuyDIY

5 жыл бұрын

There is no problem with water for cooling. When the boat is loaded with men and decoys, the cavitation plate is under water.

That motor looks too high

@OldGuyDIY

6 жыл бұрын

It was too high. It worked great in about 6" of water in the duck swamp but did not sit low enough in the water to do well in open water. I ended up reducing the rise to 2" and found that to be a good compromise.

Transom not tranzum