prop question

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truckhuntfish

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I am new to actually having a motor with prop options. my motor has 3 different options , 11 , 13 , 15 pitch. it came with a 13 pitch on it and it is ok but you always want more right ? for more top end / speed would i go to the 11 or the 15 ? Motor is a 30 hp on a 14 foot v bottom.
 
A tach is a must when playing with outboard props.
Theres a "tiny tach"that can be installed aftermarket.
If your motor can get the proper rpms with the 15 pitch, it would go faster.If the motors rpms are to low,not only will you go slower but will end up hurting your motor(lugging it).
RPMs are key,thats why a tach is pretty much a necessity.

A quick way to think of prop pitches is for every turn of the prop,whatever the pitch is how many inches you should move.
So,1 revoltuion with the 11 pitch=11inches;15 pitch=15 inches.
This isn't exact as slippage and other factors come into play.

So,you may be able to turn a 15" prop and that would make you go faster.(lugging motor just as bad as to much rpm)
Slower to plane,may not without moving weight around.
The 11 pitch would make you jump onto plane quickly,good for heavy loads but you may go over the suggested rpms at WOT.(high rpms bad also)
 
since your motor has "options", it means the manufacurer already factored in the variables and 11 to 15 is the safe range. i would not suggest changing the "stock" prop until you are certain that you need more. the 13 might already be just right for your application.
without a tach, you will feel this when you run 3/4 throttle then go to WOT and have increase in rpm but little to no increase in speed. opposite is true if you go WOT but feel only slight rpm increase.
note: go WOT only for short bursts.
 

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