Water over transom...

[BunLai]

The boat is currently on a lift at my cabin about 100 miles away, so I don't have quick access to take a better photo, but attached is one that I have. The motor is basically mounted with the clamps flush on top of the transom. I've adjusted the trim to different positions but not noticed much of a difference. I thought about getting a manual jack plate to dial in the best height to prevent this, but was just looking for other ideas before I do that. It does not seem like a jack plate should be needed to keep the motor from pushing water back over the transom on a small outboard like this.

I have a grizzly 1448 with 20hp tohatsu tiller. My transom is 17.5 and the tohatsu short shaft is 16". Tohatsu manual says to mount the engine so the cav plate is 1/4' to 1" below the bottom of the transom.I was getting back spray over the transom at wot until I mounted a jackplate with 6" setback and lowered the engine. I believe the tohatsu 15/20 hp and merc 15/20 are the same engine [made by tohatsu] With a jackplate you can adjust your cav plate height. Good luck.

How did you lower the engine with a jackplate? Could you share a photo. I’m having a too high problem on my 17.5” Grizzly. Thank you

 

[ProduceMan]

Did you solve the spray problem? Do you have enough bite for the clamps on the transom with up to a 1" spacer on top of it? Try that. If not look at the replacement poly motor boards for kicker brackets, their thickness gives you a 2" setback. I was lucky enough to find a used Garelick bracket with a 135# weight rating board at a salvage yard. Mounted it and got the setback and lift I needed.

 

[enwez]

I'm currently not done yet, but I'm in the process of making a jack plate for my long shaft motor to fit on a 15" transom. I need to raise it a good 6.5", and will have about 3.5" set back when all said and done.

So far I'm at $45 in cost and will need to by 1/2" stainless hardware and I should be done. Not bad, especially since the cheapest jackplate I found online was $180! (Mini-jack is ~$100 but only gives 3" lift).

The design is pretty much the same exact concept as the Dillion racing one, but I sized the holes and mounting locations to fit my needs. Didn't want to spend the $10 on the plans when I'm a mechanical designer myself... (and I'm cheap)

 

[marshman]

Without more info, I say the motor needs to be raised..

 

[turbotodd]

Everybody makes their boats differently, and everybody makes their motors differently. There's minor differences in lengths between all of the motor manufacturers. One might be 15.6", another 15.0", etc. Then the angle of the transom is different between boat builders; the keel is deeper on some than on others, the "vee" angle is different between different boats, etc etc. So that's why you have to "play" with your setup.

If you're getting spray between the transom & clamp, the motor's too deep. Raise it up & it should solve the spray issue AND pick up some speed.

They all tell you to start with a low mounting so that you don't run out & burn up your motor.

 

[jcunard]

did the original poster solve their problem?