Originally Posted by tonymac
OK I'm a newbie - but what is a 'flush muff'? I have a flush hose in my Mer Optimax which I use to flush the engine after a run is that what it is? Is is safe to run an engine with water running through it on the flush hose?
Most manufacturers state that the engine should not be run while flushing through the hose connector. Suzuki is, as far as I am aware, the only exception (they used to have a link to a video on their site that showed an outboard running with the hose connection supplying cooling water.)
Flush muffs are a couple of suction-cup-looking thingies mounted on a wire frame that cover the water intakes on either side of the lower unit. One or both of the cups have a connector for a garden hose. You put the muffs on, connect the hose, turn on the water, and run the motor at idle. The impeller circulates water through the motor and flushes out salt and stuff.
Later motors have a dedicated port that you hook a hose up to. Same thing, without having to run the motor (though many will argue about effectiveness, for some reason or another.)