what should rpms read

[tony77]

I have 86 sea ray 170 volvo according to speedometer with throttle wide open boat does about 40.....although the rpms only read about 3000 at times it feels like the engine is holding back.....when i cut back on throttle rpms drop to about 2500.....still going about 20 or so.....does this sound right

 

[hoot]

Re: what should rpms read

what is the prop pitch? seems like wot on your boat motor should be more than 3000rpm. on my boat, with a 21pitch prop, i get 10 mph per 1000 rpm. 2000 rpm=20mph, 4000 rpm=40mph.