1975 Johnson 115 running out of fuel to soon

[jwigg21]

Hello I am running a 1975 Johnson 115 on a 15ft Phantom ski boat. I put 6 gallons of 93 octan gas in my tank and ran it for less than hour at about 5rpms the entire time and it was done. Is this suppose to be happening or do I have a problem? The engine starts up and runs great with out a problem. Is there anyway I can save my fuel, like do something with the carbs, change my fuel filter, pump, not run it at top speed the entire time? Or is this how this engine is suppose to consume gas?

 

[RoughFishAssassins]

Re: 1975 Johnson 115 running out of fuel to soon

I have a '77 of that hp and it is a thirsty beast. When I go out, I typically have 12+ gallons onboard, but it dont take long. I would check things out though, sounds like there might be a leak some where. or it might just be that thirsty too

 

[Solittle]

Re: 1975 Johnson 115 running out of fuel to soon

Rule of thumb is 10% of hp at WOT so for your 115 that is 11 gal per hr.

Best way to save fuel with that engine is to ease off the throttle - like instead of running at 5,500 rpm run at 3,500. Forget tinkering with it.

 

[jwigg21]

Re: 1975 Johnson 115 running out of fuel to soon

Thanks you all for your advise. I guess I will just take a gas can with me when I go out just to be on the safe side.

 

[Will Bark]

Re: 1975 Johnson 115 running out of fuel to soon

In my area that extra gas can is known as the "get home can".

 

[oldman570]

Re: 1975 Johnson 115 running out of fuel to soon

^1 on Solittle's input. As stated those motors are fuel eaters when run at WOT, and most all motors of that size are. JMO
Oldman570