77 johnson 115 questins

[bassfisher2010]

OK I have a fairly healthy 77 115. The compression is 125 on cylinders 2,3,4 and about 122 on #1. I have her mated on the back of a 16ft venture magnum tri hull bass boat with stock prop and properly set Jack plate. Also installed transom saver after I had to rebuild thet ransom. Anyways what kind of fuel mileage can I expect? I have a 13 gallon tank with a spare 5 gallon. And can't fuel at marina BC 1 its about 1.00 more a gallon 2 ethanol and 3 water in their tanks. Should that be enough fuel for a days ride? Also any guesses for top speed with 2 people and light gear? I will be taking her out for the first time Monday. Also engine is ready for a decarb is 1 gallon pre mix and one can sea foam the right mixture? Will I gain some slight compression? Thanks

 

[bassfisher2010]

Re: 77 johnson 115 questins

Bump

 

[boobie]

Re: 77 johnson 115 questins

The old rule of thumb. A mtr will use 10 % of the HP at WOT. So, you would use 11.5 gal/hr at WOT.

 

[alexander 2]

Re: 77 johnson 115 questins

You will use 1 gallon of gas per hour for every 10HP at full trotle. So dont go too far from the ramp or you may hve to padle back a long way. Your speed should be about 25-30 MPH depending on conditions

 

[bassfisher2010]

Re: 77 johnson 115 questins

Well just an update she's burning 6 gallons an hour at wot at 54 MPH. (By GPS) and cruising at 30 burning about 1.5

 

[trendsetter240]

Re: 77 johnson 115 questins

Well just an update she's burning 6 gallons an hour at wot at 54 MPH. (By GPS) and cruising at 30 burning about 1.5

9mpg (54 mph / 6 gph) seems awfully good for a 77 2-stroke. Might want to check those numbers again so you don't unexpectedly get stuck out on the water.

A good rule of thumb for how much fuel you will need is 1/3 a tank to get where you're going, 1/3 to get back and 1/3 safety reserve.

 

[bassfisher2010]

Re: 77 johnson 115 questins

I taught that was awfully good also bit its only an 800 pound boat so that could make a difference I guess