need help with idle problem

[raray1221]

i have a merc classic 50 4cyl and after cleaning the carbs ansd setting both 1 and 1/2 turns out. The engine idles ok on muffs but it the water it pretty much will not idle. Everything electrical is either new or works fine, bothe carbs and fuel pump has been cleaned and rebuilt, all hoses should still be fine (checked about 2 months ago). really stuck on this one, what shouuld i do?

 

[CharlieB]

Re: need help with idle problem

1 1/2 turns out on the idle mixture screws is the STARTING point to the idle mixture. On the hose this may be fine but once on the water it is too lean yet. On the hose adjust the mixture to the best idle then turn the screws out an additional 1/4 turn.

Once on the water readjust the screws to best idle in forward gear, then slam the throttle wide open (still in gear), if the motor hesitates or bogs any then turn the screws out an additional 1/16 turn (about the width of the screwdriver blade slot) and repeat the WOT acceleration test. Continue richening the the idle mixture until ALL hesitation/bog is gone.