1871 60hp using too much fuel

[NZ-Kevin]

Hi, I've just discovered this forum and need some help. I have a 1971 60hp Johnson outboard on my boat (60ES 71C). It seems to be using far too much fuel, 20 litres (4.4galons) for 25-30km (15-18 miles). It's only a 16' fibreglass boat, so this seems a lot to me. I have a manual on order, but it won't be here for a couple of weeks and I'd like to use the boat before then. I had a quick look and the choke is set to "off", but it still starts from cold which seems to indicate it's running rich to me. Can anyone advise me of how to set the carbs up? I do have a full workshop, and am used to working on engines -but they have always had four wheels attached to them before.

Thanks
Kevin

 

[kenmyfam]

Re: 1871 60hp using too much fuel

1871 !!!! Wow that's an old motor in your title.
Seriously though MPG is not feasible in boating. You have to take currents, wind, waves into the equation. Would your car get the same MPG going uphill constantly ??
Easiest measure is GPH (gallons per hour)
Your motor should use around 10% of its HP rating in gallons per hour at WOT (wide open throttle) and significantly less at cruising speeds. In your case 6 gallons per hour at WOT.
Welcome to iboats

 

[NZ-Kevin]

Re: 1871 60hp using too much fuel

Thanks for that. I think we travelled for a max of 30 minutes, which would give something like 8 GPH, which does sound too much.