How many rpm's for a FStroke 115 Yamaha?

[rjv57chevy]

I've got a 2006 model 115 Yamaha 4 stroke pushing a flat bottom boat. What rpm range should this motor be at WOT. I've always owned 2 strokes and know the answer for them but I wasn't sure if it is the same for a 4 stroke. Right now at WOT it only turns up to 4900 rpm's (once it hit 5100). The motor only has 15 hours on it. I can change the prop but I don't want to blow the engine with too many rpm's. I was thinking about lessening the pitch 2 degrees so it would run around 5500 rpm's. I know, I know, I can read the manual recommendations but I wanted some opinions of some four stroke owners/mechanics. What is my limit on this engine.

Thanks for any input,
Rodney

 

[rodbolt]

Re: How many rpm's for a FStroke 115 Yamaha?

5000-6000 is the operating range, the rev limiter will grab it at about 6200.
try to prop it with a light load for about 6K.
4900 is overpropped and you will start making oil with it.
overpropped EFI 4 strokes will make oil regaurdless of operating temps or engine speeds.
making oil is good, just not in the motor.

 

[bossee]

Re: How many rpm's for a FStroke 115 Yamaha?

Hi,

My Yamaha F115 with Yamaha Black Steel prop 13 x 19 has 6000 rpm at full throttle on my bowrider/DC type boat, 19 ft.
I would aim at at full throttle 6000 rmp when selecting prop. Lightly loaded boat.

/Bo