i own a 2001 merc 60hp 4 stroke, big foot. i had these problems when it was new. they made it run okay but near end of warranty it started doing it again. the dealer took it in and drained and cleaned the tank (20 gallon)and the carbs (4). they also put one of the inboard engine water separator/gas filter units on the boat. but now its doing the same thing.

what the problem is that these 4 strokes with carbs have very small jets that are easily clogged so the motor runs like crap particularly at idle and acceleration

i talked to a different dealer and was told he was working on a 40hp merc 4 stroke with carbs that they had done all the normal maintenance and still had problems. he said he called mercury tech support hot line again and this guy him that there is a kit for these motors to rejet them. they won’t meet the emissions standard afterwards but supposedly will run just fine

i haven’t done this yet but am considering approaching that dealer or the original selling dealer to see if the factory will do something. it’s really BS that an essentially brand new motor would run that crummy, even when it was at its best it wasn’t smooth at idle.