Idle Speed

BrianMarks

Recruit
Joined
Jun 25, 2012
Messages
2
Good Morning,

Just a quick question - I was running my boat (1985 32' Carver w/ twin 2004 5.7 Mercruiser Horizon MPI engines and Hurth gears) yesterday; the engines ran good, but when coing to the dock the stbd engine wouldn't go back to slow idle (650 rpm) it stayed at 750 rpm. I checked for binding linkage, everything was fine. After shutting down and starting up two times, it idled right down.

Not a big deal in the whole scheme of boats, but I like to keep her running as good as I can. I don't have serial numbers handy but the engine was built in April 2004
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Idle Speed

Next time it's idling high, disconnect the throttle cable from the engine and see if the idle comes down. The cable could be worn inside and a bit of slop is building up and not pushing the linkage all the way closed.
Could also be a sticky IAC valve.
 

BrianMarks

Recruit
Joined
Jun 25, 2012
Messages
2
Re: Idle Speed

Thank You, if it happens this weekend I'll give your suggestion a try.

Brian
 
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