Prop too high rake??

[seapro_stevo]

2004 18cc sea pro with a f115 yamaha turning a Stiletto 13 1/4 x 17 SS prop. max 5500 to 5600 rpm at about 43 mph. Boat performs decent, but seem that the motor has to be trimmed down pretty far to keep it from porpoising. im also using trim tabs, but im thinking that the prop may be trying to lift the bow too much causing the porpoising and need for excessive trim. any tips or recomendations on diff prop?

 

[180shabah]

Re: Prop too high rake??

...any rocker to the hull?

 

[seapro_stevo]

Re: Prop too high rake??

sorry...im not exactly sure what you mean by rocker. it looks like a standard deep v hull

 

[Black as]

Re: Prop too high rake??

2004 18cc sea pro with a f115 yamaha turning a Stiletto 13 1/4 x 17 SS prop. max 5500 to 5600 rpm at about 43 mph. Boat performs decent, but seem that the motor has to be trimmed down pretty far to keep it from porpoising. im also using trim tabs, but im thinking that the prop may be trying to lift the bow too much causing the porpoising and need for excessive trim. any tips or recomendations on diff prop?

Where does your cavitation plate sit in comparison to the bottom of the hull.

 

[180shabah]

Re: Prop too high rake??

sorry...im not exactly sure what you mean by rocker. it looks like a standard deep v hull

Hook (concave) and rocker (convex) are both deformations of the hull surface, usually from improper storage or trailer setup.

Place a straight edge along the hull, starting at the transom running forward. The first 4-5 feet should be flat. If the surface bows outward then it will cause the hull to "rock" or porpoise. If it is bowed inward, it will "hook" and dig the bow into the water.

Just want to make sure the running surface is clean and straight before you go chasing your tail on prop selection.

 

[Dhadley]

Re: Prop too high rake??

Steve, where do you live?

 

[seapro_stevo]

Re: Prop too high rake??

cavitation plate is just above bottom of hull...maybe 1 inch. i will try to get a straight edge on the hull when i get home tomorrow.



Dhadley.... i live in beaufort sc

 

[Dhadley]

Re: Prop too high rake??

I'd be very tempted to try the Turbo FX4 series prop.

 

[seapro_stevo]

Re: Prop too high rake??

Hook (concave) and rocker (convex) are both deformations of the hull surface, usually from improper storage or trailer setup.

Place a straight edge along the hull, starting at the transom running forward. The first 4-5 feet should be flat. If the surface bows outward then it will cause the hull to "rock" or porpoise. If it is bowed inward, it will "hook" and dig the bow into the water.

Just want to make sure the running surface is clean and straight before you go chasing your tail on prop selection.

hull seems to be nice and flat

 

[seapro_stevo]

Re: Prop too high rake??

I'd be very tempted to try the Turbo FX4 series prop.

anyone else have any good suggestions?