Cruising RPM's

[mshostek]

I am a first time outboard motor owner. I have a 1995, 115 hp, two stroke, oil injected motor pushing a 24 ft. poontoon boat. I usually cruise around at low RPM's. My question is: what is the max RPM's a motor like this should be driven at for extended periods of time? In other words, if I want to get to a specific place, is it safe to run the motor at 4000 to 5000 rpm's for say 10 to 15 minutes?

 

[Scaaty]

Re: Cruising RPM's

Anywhere up to 5200 should be fine, but I would throttle back untill it FEELS right...pontoons aint race boats

 

[Silvertip]

Re: Cruising RPM's

That motor will run at 5500 RPM for years if its maintained properly, decarbed periodically. Pontoons typically are used for slow cruising and that motor works well in that application. But -- open it up for a mile or two to clear it out. Prolonged low speed operation will do more damage than prolonged wide open throttle operation. In your application, that engine should be decarbed (carbon removed) every year. There are many posts here on how to do that. Running SeaFoam or Engine Tuner in the fuel helps.

 

[WillyBWright]

Re: Cruising RPM's

5250 for the inline-4 115s. All day long.

 

[Silvertip]

Re: Cruising RPM's

Oops -- thought I was still on the Johnson forum.

 

[mshostek]

Re: Cruising RPM's

Thanks to everyone. As for decarbing the motor, what do you recommend? I will run some SeaFoam or engine tuner but what else do you suggest?

 

[Silvertip]

Re: Cruising RPM's

Go the Frequently Asked Questions at the top of this forum. Then scroll down the list of topics and about the fifth or sixth from the end of the list is a Decarb procedure. Its titled "Decarbing Your Engine -- How and Why". SeaFoam or other Decarb products are used for this procedure. Using these products in small doses in the fuel is a preventive measure.