Re: cruise speed and rpm
 

3200 RPM=46 MPH
4 people 170 gallons of gas.

Re: cruise speed and rpm
 

i think more hp will put me where i wanna be :D if i cruise at 3600 the boat is so heavy and solid it seems like your just putting along, once you get going over 70 the boat rides sweet and it just feel great the way it runs out, i want to cruise at this speed which is about 4700 rpms, is that to high for long runs? the motor sounds like its in its sweet spot and i think thats where the torque peak was on the dyno, im 4.5 stroke 577 ci.

Re: cruise speed and rpm
 

I had one boat I put bigger pitch props on so I could cruise at 70 and only turn 4200. Had a little more problem getting on plane and lost about 8mph top speed but got great fuel mileage and no broken engines. Dropped my wof throttle to 5400 from 6000. NA 540's

Re: cruise speed and rpm
 

I usally run about 3200-3400 on the way out and the way back the RPM goes up :drink:

3200 is about 56-58MPH

Re: cruise speed and rpm
 

Most boat tests I read in magazines , show best fuel economy for I/Os in v hulls (not cats) to be between 3000 and 3500. Mine at 3000 gets me 50 mph(actually 51.1 gps) which is very comfortable. Occasionally I'll run my "cruise" up to 3500.

Re: cruise speed and rpm
 

My 540 Is The Same Way It Does Not Seem Happy Until 4000 Rpm Give Or Take..........my Boat Is Also Heavy And Does Not Really Air Out And Ride Till About 60mph........plus Who The Hell Wants To Know Cruising Speed I Want Ruff Water And To Haul Ass..............i Know Rat Will Agree With That.....hence Giant Blower Motors.....

Re: cruise speed and rpm
 

Yes! :D

Re: cruise speed and rpm
 

72 mph @ 3700 rpm.