Porpoising aluminum boat.

[Bwalker]

I have a semi v hulled jon boat with a yam 60 on it that porpoises unless the motor is trimmed down quit a ways. IE the flat, top surface of the cowl is not paralell with the water, but rather lower in the back than front. The AV plate is level with the hull bottom. What can I do to fix this problem?

 

[Silvertip]

Re: Porpoising aluminum boat.

Nauticus Smart Tabs. No boat should be without them.

 

[Belchy]

Re: Porpoising aluminum boat.

You could also try distrubuting some of the weight around to different locations in the boat, such as adding a litter more to the bow and taking some away from the stern, should help..<br /><br />Belchy

 

[JB]

Re: Porpoising aluminum boat.

Duplicate post. See Boats.

 

[larsand]

Re: Porpoising aluminum boat.

Does anyone have more thoughts on Nauticus Smart Tabs

 

[sandiegosteve]

Re: Porpoising aluminum boat.

Get a hydrafoil for the cavitation plate. I think I put the stingray on my Aluminum boat and it was great.

 

[larlarsa]

Re: Porpoising aluminum boat.

or add a pair of transom wedge to the motor between transom if you don't want to move anything around the boat,this will make more negative trim to the bow come downward,it may help.

 

[robert graham]

Re: Porpoising aluminum boat.

My 18' semi-V jon boat with 90HP Yamaha porpoises unless trimmed down quite a bit, so I just leave it mostly down, don't run wide open much at all because motor sucks so much gas, usually cruise in the 2500 to 3500 RPM range. Guess if I did a lot of wide open running I'd need a set of those smart tabs! I just can't cut that 9 gallons per hour! Good Luck!

 

[steelespike]

Re: Porpoising aluminum boat.

Does anyone have more thoughts on Nauticus Smart Tabs

From my experience here;they work well ,have excellent factory support.
Plane easier stay on plane with less power eliminate no wake speed wander.
All trim tabs if too agressivly applied can reduce top speed.
While foils can work they sometimes create worse problems and they do apply force to the motor/suspension can lower top end speed.

 

[JimS123]

Re: Porpoising aluminum boat.

This is not a probelm that can be solved with trim tabs or a hydrofoil. In fact, its not a problem.

Just trim the motor down to where the boat runs smooth!

 

[5150abf]

Re: Porpoising aluminum boat.

Don't know how your boat is set up adn you don't post a size but I would imagine all or most of your weight is in the back.

Try moving a battery and the gas to the bow, that should certainly help and may get you some more speed for free or the cost of some gas hose.