Porpoising at medium speed

[Greg M]

I have a Nitro 290 Sport with a 225 Optimax on it and a 9.9 kicker. The boat bounces terrible at medium speed say 25-40 mph. Above 40 mph the boat flies and cuts thru water like a hot knife thru butter. When getting to the speed of 40+ or when slowing down from 40+ the boat bounces all over. Any suggestions or ideas. Bass Pro says the pitch of the prop is fine. I would like to be able to go 30-35 mph without throwing someone out of the boat.

 

[Scott Hammer TOXIC]

Are you trimming down when you slow down?



TOXIC

 

[Greg M]

Yes. It is not trimmed very far up when on plane at 45-60mph. Cannot trim down very much.

 

[Luke Musto2]

WHen it begins to porpoise, trim down until it stops.

 

[Mike Zechman]

It may be a sport issue. I have the 189 sport, 200 opti, when i first got mine it would also do this after on plane, and fine after you were runnin fairly fast, the nitro dealer I ordered through told me to experiment with the plugs on the prop(25 tempast+)and adjust weight distribution. I now leave 3 plugs in, which gets me on plane good, with al 3 out it will porpose, but not with all of them in, just a thought