I have a 1979 100hp johnson 4cylinder on a 15 foot cobia, and was wondering if anyone could tell me what the typical fuel consumption is. just bought the boat, and am curious as to what i can expect.
10 gallons per hour at wide open throttle. MPG can be calculated based on the speed WOT gets you. MPG at anything less than WOT is strictly a guess and the only way you can pinpoint "exact" MPG is with a fuel flow monitor. As a wild guess, 3-5 MPG.
I had a 1979 70 hp a number of years back, great motor. We averaged 6 gal per hour at cruising speed 24/26mph. And yes almost 8 gal per hour at WOT on 18 ft alum.
