ok, my problem with loosing power has been solved and the fix was cleaning the carbs out of gunk. engine runs great above idle but the engine seems to stumble at idle.

its idling around 800-850rpms but every 5 seconds maybe it will suddenly seem like it misses or something. the rpms will drop down to like 500 and then it will regain itself and idle normal for a few seconds till it stumbles again. when it stumbles sometimes it will make a little poof noise. also sometimes when starting itll start and stall once or twice and then needs to be cranked for a couple seconds before itll keep itself running.

not sure if these carbs maybe need to be tuned or what. any other ideas on what to check for this issue. im gonna chage the spark plug wires this week but i doubt that would cause this.

Thanks in advance

Maybe the timing is off a degree or 2.

i have a 2004 mercury 60 hp..3 cylinder..have had it worked on twice..does the same thing,rough idle and stalls sometimes idling in to dock and i always have to use the choke to start it and it usually coughs and stalls at least once..if you find the problem please post..good luck..my next boat will hopefully not have a mercury on it if i can help it!!!!!!!

actually worked on it today and i believe the issue was the low speed/idle adjustment screws. they were all set different and when i adjusted them about 1/4 turn out more than where they were set as well as evening them up it seemed to stop the stumble and poof. gotto take it on the water but it seems good as of now