240EFI ISLANDIA Fuel economy question

[SeptemberC]

This will be my first summer with the Islandia. Although I'm still working on "fine tuning" the engine performance (need to verify correct timing) I was curious if anyone had ever really paid attention to when you got the best fuel economy. The reason I ask is 2 things.... We will be going on vacation to Norris Lake in Tennessee. I'm not familiar with the area. I do know there are several marinas that I will be able to refuel. Getting from point A to point B .... I know that slow speed & high RPM is sucking fuel like crazy and full throttle cruising is also consuming quickly. I'm just trying to figure out if there's a "sweet spot" for fuel economy for getting from A to B...

LOL - Having said all of that I am aware and guilty of saying to others...if you have to ask how much gas a boat is gonna use then you probably can't afford it.

I'm just looking for some advice and experience thoughts.

Have a great Memorial Day weekend everybody! ️️

 

[Dr Honda]

Full throttle is about 26 GPH on the 240 engine. As I recall... the "Sweet Spot" for the islandia was around 25~27 mph for the best range. (about 1.9 mpg) AND... that should get you about 150 miles on the tank.

 

[henryb]

I think that with most boats, the best gas mileage would be the lowest engine rpm's that keep the boat on plane continuously.

 

[SeptemberC]

That was my thought too! Thanks for confirming.

 

[SeptemberC]

So when you find out that you've only been running on 5 cylinders for most of the summer and then you replace the bad coil so that you are now running on all 6 cylinders. . . Your fuel economy is A LOT better! :facepalm:

 

[henryb]

Incredible what one extra cylinder can do!!! LOL

 

[SeptemberC]

Incredible what one extra cylinder can do!!! LOL

IMAGINE . . . .2 MORE!!! :thumbsup::thumbsup:

 

[henryb]

Woohoo!!! I like the way you think!!! Yaaa.

 

[Dr Honda]

Yep... I knew your boat was running a little slow. BUT, be thankful that it was a dead coil, and not a dead injector. At least you were keeping that cyl oiled, and cooled.

 

[Lumps]

So when you find out that you've only been running on 5 cylinders for most of the summer and then you replace the bad coil so that you are now running on all 6 cylinders. . . Your fuel economy is A LOT better! :facepalm:

How did you figure out you were down a cylinder? I have always worried about this

 

[SeptemberC]

I had changed the spark plugs in June. Noticed the RPM's were down. I posted my concern. (Dr Honda suspected low compression on a cylinder but they had all been checked when we put new plugs in. So we kinda ignored BAD ME). I then noticed a very slight hiccup at full throttle. It was suggested that I check plugs... Bingo! One plug looked brand new still. It turned out to be a bad coil pack.

 

[Lumps]

good detective work!