At idle RPM goes down for a second

[BarflyRIB]

I have a Mercury Optimax 200 HP Saltwater that runs great. But when I flush the engine at idle (about 600 RPM), it goes down the RPM sometimes for not even a second. It's like there is a moment he has no fuel enough to run, but it never dies, so I'm not so worried about it.
Do you guys know this phenomenon?

[Turbodiesel]

Dont worry about it, im guessing your flushing it on muffs or the attachment. Its because there is no back pressure on the exhaust as its not in the water and makes it tick over a little ruffer than it would if it were in the water. It's normal!!!

[BarflyRIB]

ok, thanks, I thought it was something like that. Pretty to know of course!