wrong prop or wrong trim angle

[narwhals]

Ok I have been boating since well a long time. I recently purchased a used Stratos 201 fish and ski which was way more of a project boat than it was sold to us as in perfect condition. After many months of everything being repaired we had the kids out tubing and we have gotten in some fishing as well, I am having a heck of a time getting this boat to plane properly under 30 mph it has a 200 hp venom johnson outboard with a 14 3 X 21 prop on it and anything under 3000 rpm"s the boat will come off plane and porpoise or bob if that makes any sense. I have never had an issue with any boat doing this so I am in uncharted waters on this matter. I would like to have kids tubing under 30 mph at 20-25 which would be much safer.I have tried many different angles on the trim to offset this issue but I have been unsuccessful on a solution. Once on plane the boat is awesome but keeping it on plane at a slower speed is difficult as the rpm's fall down to 2500 rpm's.

 

[Jeep Man]

Sounds like you need trim tabs. Cures porpoising and much better control at lower speeds.

 

[crb478]

Trim tabs or smart tabs would probably help, but how is the motor set up? It sounds like raising the motor, if possible, it might plane better. Next what is your WOT RPM. Your prop should be matched to that range. The hull shape also has a lot to do with how a boat planes. I have a CC with a shallow v stepped hull and it planes best at 3000 rpm and up, and I use smart tabs. It is stable fishing and trolling, and runs well on plane but does not jump on plane at low rpm's.

 

[narwhals]

Thanks for the response. I haven't had the boat all the way up to WOT but the numbers range from 5000-6000 rpm"s with 5500 rpm's being the number that seems to correspond the best with this motor.I am in the process of replacing both steering cables as the boat only came with one cable attached to the steering wheel and the outboard. I will look into smart tabs unless trim tabs can be installed easy enough. The stern of the boat has a funky configuration to accommodate the outboard and the individual swim steps.