What height for cavitation plate?

[mickjetblue]

I use my 18hp Nissan o/b on my jon boat often in a shallow river.
The cavitation plate is now 2" below the bottom of the boat.
Would it be more efficient if I raised the o/b on the 20" transom so that the
cavitation plate would be even with the bottom of the hull?
I am hoping for better performance and less risk of hitting rocks.
Thanks.

 

[TOHATSU GURU]

Re: What height for cavitation plate?

Up to 1 inch above. It's done by trial and error to determine where the sweet spot is on each application.

 

[steelespike]

Re: What height for cavitation plate?

You may have to build up the transom.If you do; try to make it so you can adjust the final height easily.Start with the antvent plate even with the bottom but try to set it up so you can have a max movement of about 1 inch in either direction.You could gain a couple of miles per hour with a little luck
Be sure it continues to pump water and the clamps have a good grip.