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Old 04-26-2014, 05:52 AM   #8
FF
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Join Date: Oct 2007
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Changing props to attempt to get a 25ft LWL to operate at almost plaining 7-7K will require a higher PM to be carried at normal cruise.

If you change the prop pitch to reach 3800 or 3000rpm from where ever it is now (2200?) at 1/2 throttle the cruise RPM will change UP by the same percentage .

So instead of an 1800 cruise it might become 2300 forever .

This IS higher up on the power band so may set you up for underloading and a slobbering engine.

As its a car engine this should not happen , but the fuel consumption will be up, and the engine life shorter from increased piston miles.

REEDS nautical tide tables can keep you out of 3K currents.

IF you attempt full throttle operation with the existing prop, a 10% reduction from whatever RPM you see on the pin is suggested.

No black exhaust smoke down 10% your fine.
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