1976 merc 40 "gnat" (4hp) won't idle

[af12]

I have an old 1976 mercury 40 "gnat" (4hp) that was rebuilt a few years ago and hardly used since. It is the 2 cylinder model made in Belgum. I took it out to get it to run and had to take off the carbuerator to clean it. It runs fine, but wont idle. When throttle is turned down to slow it starts to die. Any ideas as to what the problem might be?

[boats.net]

Sounds like either you did not throughly clean the idle circuit in the carburetor, could be a timing issue or could even be as simple as carburetor adjustments.