I have a 1961 Johnson 40 hp Outboard, Gas efficiency?

[Saskatoon2005]

I am wondering how much gas should I go through with my Johnson 40 Hp Outboard? I realize that it is spinning at 5,000 rpm but I go through 6 gallons of gas in like a day and a half. Not trolling even, just head out to a fishing spot and then shut her off. There seem to be a lot of unburnt fuel coming out of her as well. Does this mean a complete rebuild, and if so, how does one go about doing it? I mean which seals need to be replaced?<br /><br />My model of outboard is a rds-23. It is an electric start. I had trouble with the solenoid so I couldn't troll with it because my battery would drain and then I couldn't restart because I didn't have a recoil starter. i didn't complain because I bought the boat motor and trailer for $250 CND.

 

[Xcusme]

Re: I have a 1961 Johnson 40 hp Outboard, Gas efficiency?

As a general rule, 10% of the motors HP per hour at WOT= gals.<br /><br />40 HP motor should be around 4 gallons per hour at WOT.

 

[lark2004]

Re: I have a 1961 Johnson 40 hp Outboard, Gas efficiency?

Also, these old Bigtwins are very thirsty engines. <br /><br />The unburnt fuel? Is that while your running.....or when the motor is stopped?

 

[Saskatoon2005]

Re: I have a 1961 Johnson 40 hp Outboard, Gas efficiency?

The unburnt fuel is from the motor running.

 

[Chinewalker]

Re: I have a 1961 Johnson 40 hp Outboard, Gas efficiency?

Those motors dump unburned fuel by design. Fuel would puddle in the crankcase and they incorporated a check valve to dump it into the motor leg, and into the water. Somewhere here on the boards someone posted a way to reroute that check valve to return the fuel to the tank. Fairly easy modification if I recall, and saves a lot of gas, too... A search may turn it up...<br /><br />- Scott