Twin mariner outboards

[paul1]

I have twin 40hp mariner outboards, same age ,same service tune up, and same throttle/control linkage position, however one engine uses up to 25% more fuel every time out, the only difference appears apart from the fuel consumption is one idles rougher than the other,
the rough idleing i believe could be down to worn dampers, and not air mix control screw
Any suggestions.?

[Searider]

Are you sure you are running them at the same speed - rev counters or "by ear"

Relying on having the throttle levers in the same position won't do it.

[BogMonster]

Originally Posted by Searider

Are you sure you are running them at the same speed - rev counters or "by ear"

Relying on having the throttle levers in the same position won't do it.

I suppose if one of them was going slightly faster it would take much more than its fair share of the load as it would effectively be "pulling" the other one, so it would then use a lot more fuel?

[Turbodiesel]

Its quite common on twin rigs with both gear boxes turning the same direction for one engine to have a much greater load than the other one. As one engine seems to pull more water than the other. More noticable when your running in a pair of Opti's on a boat one will run in much quicker than the other as one as one has a greater load.