Prop Depth?

[armysfcret]

OOps, guess this should be in General Outboard Questions.<br /><br />Just some questions from a new 'toon driver. <br /><br />What is the correct depth that should be set for the prop on a pontoon. It seems mine is way too deep. It is my understanding that the cavitation plate should be just under the surface of the water. Believe mine is about five inches or more below the surface with no load in the boat. <br /><br />Wouldn't it be feasible to have the bottom of the prop just above the bottom of the pontoons. This would also help to protect the prop from hitting in shallow water as the pontoons would hit first. <br /><br />What am I missing here?

 

[ZmOz]

Re: Prop Depth?

The cavitation plate should be about 1 inch below the water when you're planing.

 

[outboardguy]

Re: Prop Depth?

On a fiberglass boat you mount the drive so that the anti ventilation plate is level with the bottom of the boat.But on a pontoon and other work barges the anti ventilation plate should be lower to make sure the prop has a good grip on the water for turning.Your engine may be a little low but I wouldn't worry about it.Or just raise a couple notches.

 

[armysfcret]

Re: Prop Depth?

Hadn't thought about the turning factor. 'Toons are certainly different animals when it comes to setup as opposed to "real" boats. Thanks for the feedback.<br /><br />Planing? I wish!

 

[rickdb1boat]

Re: Prop Depth?

Where does you cavitation plate sit in relation to the logs when out of the water? Should even with the bottom of the logs. This is generally speaking, of course. Every one I've had has been that way, though. The cavitation plate while just sitting in the water will be about 5 or more inches below the water, do to the weight of the boat. When you are moving, the plate will be higher in the water, do to the angle of the boat from front to back changing and leveling out. I think you are real close. This is where mine is:<br /><br />

 

[riverebel]

Re: Prop Depth?

I have a 22 ft Fisher pontoon with a 60 hp Mariner.The cavitation plate sits about 9 in.below the waterline on the toons at the back.The motor sits all the way down in top hole. Does this seem too low?

 

[riverebel]

Re: Prop Depth?

^

 

[widowmaker666]

Re: Prop Depth?

How will it effect my control (speed/steering) if the anti-ventilation plate is 1" above the bottom of the hull vs. 0-1" below the bottom of the hull? I am running a 15' fiber glass with a 50 HP Mercury.