Thinking about hanging a smaller motor on my old tri hull. It had a 78' 70hp johnson on it before and I wish I hadnt sold the motor. I know that usually the bigger the motor, the less fuel efficient they are. How much difference is there between a 90hp-140hp johnson or evinrude and a 70hp? I might end up going back with a 70 or smaller but would really like a little bit more power.
Actually if you think about it a higher horsepower motor would be more fuel efficient. You can attain the same cruising speed with it as you would having to run wide open with the smaller HP motor. If I wanted something that would have some ooomph and cruise well and be reliable I would look for a 115 HP 60* motor.
Thats kind of what I was thinking but was hoping someone had first hand experience with the different motors. Ive only had a 70 and a 175, so I cant compare the two! I have heard that the 140 is not near as dependable as the 90 or 115 but I dont know for sure.
The 1st bass boat I had was a 83 Bassmaster Bomber with a 77 70 hp Johnson. I owned that boat for about 5 years. I ran the same route many times in that boat and always burned 4 gallons of fuel. I now have a 99 150 and run the exact same route and burn excatlly 4 gaollons of fuel. It has been my experience that a 150 direct injection gets the same fuel milage as a 70 hp carburated motor.
I have no idea what my speed was with the 70 hp motor because that boat did not have a speedomoter or gps. With the 150 I cruse at 45-50mph. I do open it up to 60mph on log straight runs but normally cruise at 45-50. My 150 direct injection motor will get me there much faster and use the same amount of fuel as the 70hp carburated motor.
If you are going to stay with a carburated motor fuel comsumpiton will go up with more hp.
The 4 stroke trend is for a reason...or two...
also running under 4k rpms saves a LOT of fuel just as cruise control on a car...
jackrabbit starts burn much fuel...
I got my 1st Four stroke after 9 two strokes and its making that $3.60 gas
seems like $2.60 gas to my wallet....I like.
Outboards are much more fuel efficient the past 10 years or so...
good luck...its gonna be enjoyable...whichever way u go...
2018 Z19/200 Optimax 2 stroker 24x3 Fury Ultrex 112
Lowrance HDS 12/9 Lives with AT 2
If you replace your 70hp old style 2 stroke with a new E-TEC 75 or 90, you will cut your fuel use in about half, plus you will save anywhere from half to tw0-thirds on oil comsumption.
If your boat is rated for 115 or better and you install a 115, then you will really like the overall performance and will still save on gas and oil.
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A Technical troubleshooter possessing more tools than talent !
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