Jon boat "plows" through the water

I have a 14' Jon with a 18HP Rude, and it does like no other boat I have ever owned. The bow will raise up like normal when you take off, but once I get on a good plane it acts like a barge, all the boat is in the water at 22MPH and it seems to "catch" on the water, almost like hitting on brakes in a car then goes again. Engine is costant, so I dont think its the problem. I have 4 "notches" for my trim, the highest trim cavitates, and the next lowest causes this problem, everyone lower makes it "plow" worse. I had some of the swept up hydrofoils on it (ones that are suspose to be out of the water on a plane) and I think they may of been the issue (but yet foils are great on the bow rider) so I removed them but have yet to take a trip with them off

Boat is set up like this

bow to front seat is "normal" except for a spot light, between the front and rear seat is a 1/2 Plywood "floor", Battery and trolling motor and tanks behind rear seat

Thanks for any help

Oh yea the prop is a 9 1/4 x 11 ......... according to the evinrude book it came with a 9 x 9 or a 9 x 10 IDK if this makes a differance

Foil x2. Get rid of that thing!

I'll bet ya a beer that's the issue.

Well I will know by next weekend

While the one time I had a foil on a boat.... it helped the porpoising..it certainly slowed things down.

I went to tabs and that stopped the porpoising without the speed issues.

Best of all is my present boat. It doesn't seem to need anything extra to work properly.

Hope removal of the foil does the trick for you. R

I had the same setup on my first boat. 18hp johnson on a 14" jon. i ran the 9 1/4x11 and switched back to a 9x10. see if your local evinrude dealer will let you use a test prop or an inductive tach and see what rpm' s your engine is turning. it may be that the prop is not allowing the engine to run at it's proper rpm range (5200-5500 rpm w.o.t) that would cause the condition you are having.

well if I can get the engine running right, Ill know if it fixed things :wink: