I have a 2002 115 evinrude ficht on a heavy boat. I had a 15 in pitch prop and got 5500 at WOT. I picked up a good 17P sst prop on ebay cheap. I only get 5000 and 5200 trimmed out as far as I can. I only pick up maybe 2 mph. My question - am I supposed to turn the motor 5500 to keep it working properly and reliably??
no you dont need to keep running at 5500 rpms that is just the rec max rpms, really to be honest running at wot all the time cuts down the life of the motor lower rpms extend life so if you got 2 mph with a little larger prop and are gonig a little less on the rpms it is a good thing means also less prop slip.
[I]TEAM CORGI DOG[I]
1996 javelin 400T /1996 Johnson 200 Venom
Just a thought and I'm sure I will be corrected if I'm wrong. But I thought if you go from an Aluminium prop to a SS prop you should run the same pitch or a pitch or two smaller??
Also with running the motor at 5000 - 5200 WOT is that lugging that motor?? If so that isn't good either. Not sure what the specs are for you motor but shouldn't you prop the motor to run at the upper rpm band for WOT?
Just some questions to ask so he isn't lugging his motor.
Joe
Joe Galada - Tamaqua, PA
2004 Ranger 521VX - Yamaha 250 SHO
Joe, I'm with you, the gurus have always said to prop the motor close to the max rpms...ie mine is 5800-5900 and I'm between 5700-5900 depending on the weather.
This site may help your understanding...http://www.boatfix.com/how/props.html
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