"Idling in gear"

[Frank O]

Mercury's shop manual for my 1994 225-HP carb two-stroke talks about checking the engine's idle speed when the outboard is "idling in gear."

This seems like an oxymoron to me. I always thought the whole idea of an engine "idling" was that it was disconnected from its drive train (propeller in the case of an outboard).

So would "idling in gear" mean to nudge the throttle forward until it goes into gear, but not give it any more throttle than that? My boat generally moves at about 3.5 mph when set to this position.

 

[Robert D]

Re: "Idling in gear"

Yes. Most older 2 strokes require you to be at an idle in gear, to properly set the mixture as well. If you try to set it in neutral, you can get a perfect idle and mixture...but when you put it in gear, the engine will die.

If you don't have a large tub of water to do this like a typical shop has, be very careful when you do it at the boat ramp while still on the trailer or tied securely to the dock. (You don't want to fall in while that prop is turning...right?)