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1976 6hp Johnson fuel consumption.

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  • 1976 6hp Johnson fuel consumption.

    I have a 1976 6hp Johnson Seahorse (6R76) and was wondering if anyone knew what sort of fuel consumption it was supposed to have at wide open throttle. I have it on a 14' aluminum boat with a max capacity of 600 lbs. The boat itself weighs about 150 lbs or so. With the boat fully loaded I can get about 7.5 mph out of it.

    It's not like I plan to run it at WOT for hours on end, I'd just like to know so I can be sure not to accidentally run it out while out on the lake.


  • #2
    The old rule of thumb for 2 stroke outboards is 10% of hp in gallons per hour at WOT. .6 gallons per hour sounds about right for that motor. I don't know how many hours I put on our old 6 Johnson as a kid, but I ran it a lot, and it seems like I could run pretty much all weekend on a 6 gal tank.

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    • #3
      If you're planning a longer cruise, bring an extra fuel tank, or at the very least a small gallon sized Jerry can with some extra mixed fuel as a get me home backup plan.
      Share A Project Page for 1971 GW Invader Banchie 13
      http://www.shareaproject.com/pages/p...,p,433,00.html
      Share A Project Page for 1976 American 18
      http://www.shareaproject.com/pages/p...,p,404,00.html
      Share A Project Page for 1974 American 15
      http://www.shareaproject.com/pages/p...,p,405,00.html

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      • #4
        It's around 10 to 12 % depending on OB fabricator provided that OB runs at max wot rpm range factory stated. You could be lugging the OB and not knowing anything about it, a induction tach will tell, revving at full wot towards the min or lugging side is bad, a less pitch prop will cure it..

        Happy Boating


        Sea Rider 320, 380 Sibs, 450 Rib, 2 Strokes Tohatsu 5,18 & 30 HP Proud Smokers

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        • #5
          Thanks for the input, guys.
          The motor is completely stock, so I have no plans on changing the prop. I also run the boat on smaller lakes and it would never take more than 30 minutes or so to go from end to end at WOT.

          With the info you guys provided even if I was getting lousy economy and burning almost double the gas I should be, I could run a 3 gallon tank for about 3 hours. That means I should almost never have to worry about it as long as I start the day with the tank full.

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          • #6
            Factory delivered props are medium pitched, probably not the best one OB needs to run inside safe wot rpm range specially if powering a large combo at wot. Can't possibly know without installing an induction tach...

            Happy Boating


            Sea Rider 320, 380 Sibs, 450 Rib, 2 Strokes Tohatsu 5,18 & 30 HP Proud Smokers

            Comment


            • #7
              Sign up today
              From the mid 70s to mid 80s we had a 5 1/2 which was a lower revving(500 rpm) version of that engine. It ran a very long time(7hr+) on the 5 gal tank.

              As for propping it, the factory prop was a 8 X 7 1/4

              iboats has a selectionand two more pitches, but they are both higher
              http://boatpropellers.iboats.com/Evi...t_id=357252807

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