Max RPM/prop question

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My 95 Yamaha 250 was running at 5400 rpm at WOT and turned 44mph on a 24ft heavy WAC deep vee hull. I performed a decarb with Seafoam kreep (great stuff!) and when I took the boat out to test run she gained 200rpm and 2mph but now is running at 5600rpm at WOT and slightly above Yamaha's rated 5500 max. Should I re-prop with a size larger or not worry about it? Current prop is a stock Yamaha SS/black 17-T that I believe to be around 15inches in diameter. I would probably skip the 18 and go for a 19 pitch if I buy a new prop.

 

[WillyBWright]

Re: Max RPM/prop question

For all you know your tachometer could be off by 100 rpms. You're fine. But it never hurts to have two props in case one gets damaged. I usually have props of different pitches rather than all the same.

 

[JasonJ]

Re: Max RPM/prop question

Is your load light? I like my motors to run at the upper limit so that when I am carrying Bubba and his jumbo cooler of food I still have some oomph. Maybe you could demo a higher pitched prop to see what happens. Run different loads, and if performance and economy has improved go with it. If no improvement is seen, then stick with the current setup. Good luck...

 

[sort]

Re: Max RPM/prop question

Load is light as I have let the fuel run down to about 20 gallons versus a full tank at 125 gallons. Probably set OK with the light load. Thanks for reminding me of this. But the decarb really seemed to bring the old engine to life, runs like a new one.