Wot

[cobia chaser]

Guys,

I hear and see everyone talking about wide open throttle. Am I really supposed to be running throttle down flat out all the time? Does it hurt anything to run at say 4000 to 4500? Isn't this rpm better for gas mileage? From my spec book, I believe wot for my 115 2 stroke saltwater is 5400. I've only had it there for for a few moments at a time, every now and then, over the last few years I have had it. I'd appreciate one of you guys that have been around for awhile, opinion. Thanks!!

[bumperfood]

IMHO you do not need to run at WOT at all if you don't want/need to. A boat engine in gear is always under load, it has been compared to a car always going uphill. I run mine at a speed and throttle position to maintain a nice plane, with about a third of a throttle left to play with. My RPM at cruise is about 3600-3800rpm, and 45kph, If I open the throttle to wide open throttle or 5500-5600 rpm, I can get to 54kph. I believe that the wear and tear on the motor is diminished by running at a lower rpm. Just my opinion though.

[robert graham]

I run my Yamaha 90C 2 stroke usually in the 2500 to 4500RPM range, mainly for fuel efficiency. At WOT it's burning through a lot of fuel for a few more MPH's...I open mine up to 5500RPM's now and then, but it sorta feels like I'm runnin' the guts out of it, but It doesn't seem to hurt anything! 3500RPM's and a cruise speed of 25MPH seems like a comfortable speed and good efficiency.

[robert graham]

Also, Google:Yamaha Outboard Performance Bulletins, for your boat/motor MPG, MPH, GPH at various RPM's/Speeds

[99yam40]

You need to run WOT to make sure your setup is propped right with your normal load and are running in the high side of your motors RPM range.
After that you run at what ever RPM you find economical or comfortable to water conditions.
4 strokes need to be run hard at the end of the day to help heat up motor and burn off water vapor and fuel in oil

[cobia chaser]

Thanks all...that's what I was hoping to hear...I do open her up occasionally and she responds well...I normally run around 4000 to 4500 when possible due to waves and such...nice plane, good mileage, and around 30 t0 35 miles per hour. I topped her out when I first got it to check for correct rpm range for the prop set up. She'll do 40 or a little better at wot..... thanks again guys for an awesome info center..sincerely appreciated!!!!!