Outboard motor ride height?

[Paul_]

I put a 25 hp Mercury on my boat. It looks to me and the included instructions that it’s seating to low.
The anti-ventilation plate is supposed to be in-line with the bottom of the boat.

I can’t raise it much more.

Any ideas? Will it affect the performance much where it is currently at?

 

[Salmo_g]

I think it's called the "anti-cavitation" plate, not anti ventilation. As best I know, the anti-cavitation plate can be any amount lower than the bottom of the boat hull, just not higher than the bottom of the boat hull. What you have showing in your photo should work just fine.

 

[wetline dave]

Being lower it may tend to lift the bow quicker on Excelleration if I am visualizing correctly Which could become an issue if dropping the hammer.

Dave

 

[Mtnwkr]

You'll lose some performance and have more spray but it won't hurt anything, maybe a couple mph. I have a 30hp on mine, I bolted it two inches above bottom of boat and could still come up a bit more.
I would move it as high as possible with the clamps and bolt it up. If you want the best performance you'll need a jackplate to get it up more.

 

[Eastside]

I put a 25 hp Mercury on my boat. It looks to me and the included instructions that it’s seating to low.
The anti-ventilation plate is supposed to be in-line with the bottom of the boat.
View attachment 33726
I can’t raise it much more.
View attachment 33727
Any ideas? Will it affect the performance much where it is currently at?

Looks like a Klamath transom. I had a 40 HP on my 16 ft Klamath and it probably was about the same height. If you would like, I can check tomorrow morning when I can pull back the cover. That boat is being gifted to my son.

 

[Evan B]

That's really low. Chances are it's a long shaft when your boat should have a short shaft motor.

 

[Paul_]

I think it's called the "anti-cavitation" plate, not anti ventilation.

That’s what I thought too. I had to google it-
“The anti-ventilation plate (AVP) does not stop or help prevent cavitation. Its sole purpose is to prevent surface air from being sucked into the negative pressure side of the propeller blades.”

 

[Eastside]

That's really low. Chances are it's a long shaft when your boat should have a short shaft motor.

Evan is correct, it is low. Too lazy to take off the cover, but here is a photo of my Klamath transom. See if there is a way to raise it. On my new boat, the Mercury outboard is not resting on the top of the transom.

 

[Paul_]

Evan is correct, it is low. Too lazy to take off the cover, but here is a photo of my Klamath transom. See if there is a way to raise it. On my new boat, the Mercury outboard is not resting on the top of the transom. View attachment 33938

Thanks.
Mine doesn’t look that much lower than yours. I’ll probably just send it and see what happens.

 

[Evan B]

Evan is correct, it is low. Too lazy to take off the cover, but here is a photo of my Klamath transom. View attachment 33938

That one looks low, too. It can effect your ride quite a bit, but if you're used to it and are ok with it, then probably no reason to change.

Here's what you want to go for.

 

[Paul_]

Th

That one looks low, too. It can effect your ride quite a bit, but if you're used to it and are ok with it, then probably no reason to change.

Here's what you want to go for.
View attachment 33940

Thanks.
I inherited the boat and got a very good deal on the motor. I’ll look into a transom jack if where it’s sitting now doesn’t work.

 

[SurfnFish]

made my own U bracket out of PT 2 x 6 and 1" ext ply to mount a 20hp xl shaft I had on a 13' SportCat. Came out rock solid.
A couple of stud embedded eye bolts, strapping and a come-along make mounting the OB safe and strain free.

 

[Eastside]

That one looks low, too. It can effect your ride quite a bit, but if you're used to it and are ok with it, then probably no reason to change.

Here's what you want to go for.
View attachment 33940

Believe it or not, mine matches the photo when it is trimmed out correctly. That boat is going to my son in Oak Harbor. It’s a 16 ft Klamath with a 40 HP Tohatsu and when it is trimmed out, it runs about 33 to 35 mph.

 

[Josh]

Evan is correct, it is low. Too lazy to take off the cover, but here is a photo of my Klamath transom.

Random unrelated question:

Does it matter if you put those transom plugs in that way, from the outside, or from the inside (assuming your boat allows easy access from the inside)?

 

[Eastside]

Never had a problem. Can’t get to it inside the hull on either the Klamath or my new Smokercraft. Always on the inside on the drift boat.

 

[Scudley Do Right]

Random unrelated question:

Does it matter if you put those transom plugs in that way, from the outside, or from the inside (assuming your boat allows easy access from the inside)?

I wouldn't put a cam lock plug in from the outside though. On a boat like yours I like the cam lock on the inside so it is easy to pull while on plane if you need to drain water.

 

[Salmo_g]

Random unrelated question:

Does it matter if you put those transom plugs in that way, from the outside, or from the inside (assuming your boat allows easy access from the inside)?

Cam lock plug from the inside only. I don't like putting any plug in from the outside, but on many boats that's the only option, in which case use a screw in plug.

 

[Pescaphile]

Putting a cam-lock plug in from the exterior is a good way to lose it. Garboard plugs screw in from the exterior, but they are secure and usually aren't removed while running to drain the bildge.

 

[RPL/LL]

Look into a mini jacket.I put one on mine worked perfect.