RPM Question

[adam24601]

Hi all,<br /><br />I have a 22 foot Sunrunner Cuddy with a Merc 5.7 V8 that is rated at 260HP. I have only had the boat a few weeks and have been doing some speed and handling tests. I'm not sure if my RPM gauge is working correctly. When I go to WOT I peg 6000rpm in the red. When doing about 30 MPH I am at about 4000-4500 RPM not in the red. I was getting around 40MPH when at 6000. The gauge will read most of the time..but not always. Should I replace it, should I just know that pushing it to 40 is not a good thing. Could my prop be off pitch? Any suggestions would be welcome. Is a gauge replacement a big job? I am pretty handy with electronics if the directions are good. The dash can not be opened so I would have to mount a gague somewhere else anyway. The engine does not sound strained at all in the 4-4500 range... Any help would be appreciated.<br /><br />Thanks,<br /><br />Adam

 

[Boatin Bob]

Re: RPM Question

Adam....I would borrow or buy a handheld tach and try that to see if the readings match, you really don't want to exceed the manufactures recommended WOT RPM's. It's hard to believe you could really hit 6000 unless you are way under propped (pitch too low)

 

[quantumleap]

Re: RPM Question

What pitch prop do you have on it?

 

[adam24601]

Re: RPM Question

I'm not sure of the prop pitch. I am going to check it out Friday or Saturday. I did not check the numbers on the prop before it went in the water.<br /><br />Adam