WOT RPM's

[dacollins]

2001 Maycraft 1900<br />2002 Yamaha F115TXRA 25" shaft (approx 100 hrs)<br />current prop is SS stiletto 13x17<br />with one person and 35gal of fuel<br />WOT is 5200. Never been more than that. Runs pretty close to that fully loaded. It has been suggested that I change to a smaller pitch prop. Does anyone have any other ideas?? WOT should be closer to 6000 shouldn't it?<br />thanks

 

[swist]

Re: WOT RPM's

What is the recommended WOT RPM range? If it's more than 5200 than you need a higher pitch prop. What other ideas are there? Either you are overpropped or you aren't. Why strain the engine?

 

[dacollins]

Re: WOT RPM's

SWIST,Operating range for this engine is 5000 to 6000rpm. I'm told that the closer to 6k, the better. I have also heard things from throttle linkage to fouled fuel injectors as causes for not reaching recommended rpm's at WOT. Again, this does not appear to be a decline in performance, rather a situation where optimal peformance has never been reached. The Yamaha performance bulletins for similar weighted boats all show rpm's between 5500 an 6000 rpm's, with a prop that is same pitch as mine. I was just trolling for any other ideas that may result in underperformance of this set-up. <br />So, should I just switch to a 15in pitch, pick up 400 rpm and go with that at 5600 rpm or so??<br />thanks<br />david