Prop 101

Can someone please explain to me Prop Pitch? I was under the impression that the lower the number, the ‘flatter’ the pitch – thus it should turn faster. Higher # = better holeshot; lower top end.

I think now I am totally wrong.

Also, I looked at a boat with a 150 Yamaha. He is running a stock 19 pitch aluminum prop. We hit 47 with 2 people and a full tank of gas. If my thinking is wrong, what would you run to maximize top speed? Any suggestions on brands and pitch (aluminum) would be appreciated.

The higher the pitch, the more water the prop grabs, which transfers into power. The smaller the pitch, the faster a pitch can turn, sacrificing power in some cases, but generating higher RPMs.
Tuck

Prop Terms Explained

Hope this helps.

Think of pitch as you would gear ratios in a car or truck. If it is speed you are looking for you want the highest pitch prop that will still allow you to nearly max out the RPMs on the motor while carrying your typical load.

As far as the boat you were in is concerned, it probably is propped right.

PTC
Can you check your link? I can’t open it.

Thanks.

Try this one Mike:

http://www.miwheel.com/MIWheel/HowToTech/Terminology/pterm_main.htm

Quote:

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Higher # = better holeshot; lower top end.

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Backward. Lower number will give a better holeshot, since it allows the motor to achieve higher RPM’s faster, generating more power. Higher pitch will get you better top-end, but you need to be careful; when I got my boat they had too high a pitch on it and it would overheat when loaded heavily.

Here’s a good article that explains it in layman’s terms.
http://www.piranha.com/bladesizes.htm