AQ120B dies after running a while

"We went out today for some cr

"We went out today for some crabbing and the engine demons are back... Last year, it was running a little rough and no get up and go, so I changed everything in the ignition system including going to Hot Spark electronic ignition. It ran much better, but not great. Got digging this winter and found a fuel pump not putting out full pressure, now we are doing a little better. Last month, I rebuilt the carb to hopefully cure the last of it. It ran GREAT, for a bit...
The launch, in everett, takes 5 min of idling out past the no wake zone, then your off. We ran out to drop the crab pots, 15 min at 3/4 throttle, no prob. 10 min of putzing around and a 30 min engine off drift for lunch. Don't worry, im getting there... 15 min back to the no wake zone to go to the beach. after 3 min of idling, you could notice a bit of a miss here and there. Took out of gear to run throttle up to clear it out and off we go. within 30 sec, the engine is barely idling and finally dies. limped to the dock and let it sit for a few. Started back up and ran on the dock for 10 with no problems so we went out to get the crab pots. When we got back and idled for 3-4 min, the same thing happened. A couple of restarts and some 500 rpm chugging got us back to the dock.
I ran for and hour at home and can't duplicate. Any suggestions?
I am guessing vapor lock or the coil/ignition module getting hot."

"It would appear that the idle

"It would appear that the idle mixture/idle speed need adjusting. Also, like I said in another post, make sure you don't see fuel in the plastic hose that goes from the fuel pump to the carb flame arrestor, as this would indicate a perforated diaphraghm in the fuel pump and the unmetered gas would cause a very rich mixture would lead to rough idling and eventually would cause the engine to eventually die."

The mixture screw is supposed

The mixture screw is supposed to be set at 4 1/2 out after rebuild and adjusted to the highest idle. Mine ends up at 6 turns out for the highest idle. does this sound right or should it normally be in more? I didn't want to lean it out too much.

"Adam, the settings in Seloc a

"Adam, the settings in Seloc are approximate. If the engine stalls and the spark plugs are fouled, to me either the idle mixture is too rich, or you could have spark plugs that are too cold for your application. Also, if it stalls at idle, the idle speed may have been set too low (it should be around 900 RPM).

When I had my AQ140 with twin Solex sidedrafts, I found those carbs were a real PITA to adjust."