Rpm @ Wot?

2

280eagle

Recruit
Joined
Sep 3, 2007
Messages
1
I have a 1999 Eliminator 280 eagle with a merc 502/Bravo 1 drive that has a 4 blade 24P S.S. prop. that tops out at about 4000 rpm @ WOT and about 4200 if trimmed. At this rpm, boat speed is about 48-52mph. I've check the throttle cable/linkages and found no binding (Butterfly flaps open full as expected). Does anybody know if this rpm is all I should be expecting from this set up? Past 454's that I've driven have topped out around 4800-5000 rpm.

Thanks
 
QC

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Rpm @ Wot?

Nice boat and Welcome to iboats. Don't recall one other Eliminator owner here. Definitely too low of RPM. Looks like the guys at Hot Boat are helping out, I would also want to make sure the tach is right. Definitely sounds slow. RPM and Speed. Good luck.
 
MikDee

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: Rpm @ Wot?

Is that a 28' boat, hence 280? If so, it seems you're overpropped, I'd say drop down to a 20" pitch 4blade to get down to maximum 4600-4800rpm, a 4blade 22" pitch prop will only give you about 200rpm more, not enough IMO.
 
QC

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: Rpm @ Wot?

MikDee,

Double check your specs, I've got 502s at 4600 - 5000 RPM . . . Yes the 280 is a 28 footer. There is sumping wrong with his numbers too. Calcs to 18% slip, he's maybe got an engine performance issue and the tach may be off. Not time to change pitch just yet.
 
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