Seem like RPM for the speed

[dcamt 0]

I have a 2002 242 cruiser with a 5.0 EFI merc I/O. When I cruise, with a light load aboard, my RPMs are 3600 for a speed of 23 mph. Does that seem high? Is there something I can do to lower the RPMs?

Tks for your input

[Rip5 0]

Are your tabs fully deployed at that RPM and speed? They should not be if that is the case. It does seem a bit slow for those RPM. You can't reduce your RPM if that is all the speed you are getting, only can try and increase the speed at same RPM with tabs, trim, clean bottom of boat, less weight/fuel in the boat. Is your prop in good shape ?

[dcamt 0]

Are your tabs fully deployed at that RPM and speed? They should not be if that is the case. It does seem a bit slow for those RPM. You can't reduce your RPM if that is all the speed you are getting, only can try and increase the speed at same RPM with tabs, trim, clean bottom of boat, less weight/fuel in the boat. Is your prop in good shape ?

 

 

Tks very much for your help. I have the trim tabs down slightly and the engine trim up slightly. I play them a bit and watch my GPS speed to see if there is any difference. My bottom is good. The load is 2 persons, 3/4 gas full, no water in tank. Does it hurt if I run at this RPM or a little over 4000?

[Rip5 0]

It won't hurt running at that RPM or even higher. You need to find the "sweet spot" for your boat where it runs most efficiently. Only trial and error will get you to that point. You should, for brief periods, run your boat at WOT, to make sure you are propped right and able to achieve your maximum recommended engine RPM.

[Artemus 0]

3600 RPM does seem a bit high for that speed. It is possible you have the wrong pitch on your prop. Try a short run at wide open throttle, and see what your speed and RPM are. Your WOT RPM should be about 4600 RPM. If it is much more than that, then you could change the prop to one with a higher pitch. Do you know what size prop is on it now?