Mercruiser 5.7 Fast Idle

[elneino]

I started my boat for the first time this year while dry docked with the rabbit ears on. The starboard engine was hard to start at first but when it started it idled at about 2200 rpms and gradually raised to 3000 rpms before I shut it off. I had just changed the gimble bearing, all the bellows and lower shift cable but I can't imagine any of that being related to the idle issue. I looked at the idle screw and throttle cable on the port engine (which runs great) and the measurements are the same as the troubled engine. The gas in the boat is old but it has been stabilized. The engines are '92 Mercruiser 5.7's with under 400 hrs. Any thoughts into what I should look for.

Thanks,
Gary

 

[Scott Danforth]

how old is the fuel? if its over a year, stabil wont even help it.

what you are describing is a stuck choke. pull the spark arrestors and take a look.

by the way, use the dang boat. boats go to heck from non-use, and your averaging 16 hours of use a year which is pretty much sitting. the average is well over 50 hours