A general prop question

[sharps45]

To run best at higher altitudes, does stepping down in pitch help, or is it more the jetting of th carb? And why? thanks

 

[TilliamWe]

Re: A general prop question

You might need to do both.
Air is less dense at higher altitude. Less dense air means less ability to produce power. Your engine is really a big air pump. So if you can't get as much air into it, you would not have as much power.
Rejetting helps even out the air to fuel ratio. Lowering the pitch would help the engine turn a higher WOT rpm if you were at see level. So with less power from the engine, you actual WOT rpm might stay the same.
Hope that's as clear as mud!

 

[WillyBWright]

Re: A general prop question

On sterndrives, changing gear ratios might also be required.

 

[sharps45]

Re: A general prop question

Thanks for the info. Sounds a little expensive either way. But, any boat owner should be rich, right?

 

[Texasmark]

Re: A general prop question

Yes. A boat is a bottomless which you pour money into.

Mark

 

[sharps45]

Re: A general prop question

I heard it this way-

B bring
O out
A another
T thousand

 

[propper_advice]

Re: A general prop question

loweing your pitch will help you gain the rpms you lose when you go into high altitudes Check out this website at www.piranha.com they have a prop with interchangeable blades so when you go up from sea level you can just switch out the blades u have with a lower pitch to keep your boat from bogging down.

--nick