Difference in prop pitch?

[gunner1]

What effect does increasing prop pitch size have on the speed of a boat? For instance going from a stock prop on a Force 50 hp outboard to one that measures 11 1/2" of pitch?

 

[SpinnerBait_Nut]

Re: Difference in prop pitch?

Prop questions and topics.

 

[a70eliminator]

Re: Difference in prop pitch?

more pitch = faster top speed less pull - too much = engine bog slower top speed
Less pitch = slower top speed more pull - too little = engine overrev

 

[steelespike]

Re: Difference in prop pitch?

more pitch = faster top speed less pull - too much = engine bog slower top speed
Less pitch = slower top speed more pull - too little = engine overrev

I would only add you can't arbertrarily change pitch.Prop selection should be based on present speed, rpm and max recommended motor rpm,with some consideration of type of boat and typical load/use and ideal motor setup.
You should also be sure the motor is in well tuned sound condition.

 

[Silvertip]

Re: Difference in prop pitch?

If you can have only one prop, it will be the prop that allows the engine to operate at the top of its recommended wide open throttle rpm with an average load. If you are going for top speed, thats the prop that will do it. Increasing pitch beyond that point begins to lug the engine and it will very likely begin to slow the boat down rather than speed it up. If you also tow water toys, that prop is less than ideal for that as you need a little more power so a step down in pitch is required, but that can result in engine over rev at WOT. If you get the idea one should have two props, you'd be correct -- one for power and one for speed. If the prop you have is proper for wide open throttle, you already have the speed prop.