Idling ussues

[Planet]

Hi I have a 2003 searay srx176 with a 3.0l mercruiser
we were out today and the idle was all over the place sometimes it would idle at about 650rpm and at other times when you come off the throttle it would idle at 1000rpm also would be hard to start and try and continue to run on when turning off I gave it a full service 2 weeks ago new impeller, gear lube new oil and filter as well as fuel filter and spark plugs Any help would be greatly appreciated

 

[Scott Danforth]

welcome aboard

check to make sure your throttle cable is not hanging up and holding the throttle open

 

[Rick Stephens]

If you don't find an obvious cause, like throttle cable or an air leak in the fuel system, do a compression check. Make certain of conditions before darting all over.

 

[Planet]

Cheers guys throttle cable not hanging up but will check for air leaks motor only has 146 hrs so puzzle solving time

 

[Scott Danforth]

if the throttle cable isnt the issue, you may have to dig into the carb and do a re-fresh.

on a side note.....you need to use your boat more. thats only 10 hours a year

 

[kenny nunez]

Can you provide a picture of your carburetor? Does it have a choke butterfly? IF it does not then the problem could also be the idle air solenoid.

 

[Planet]

I intend using my boat more especially as I am coming into summer now only purchased it back in May
choke does have a butterfly I read more of my workshop Manuel overnite and went out this morning and reset all my carb settings back to factory starting point it is definately better but just not quite there yet

 

[kenny nunez]

If the throttle is closing and the idle mixture screw is @ 1.5 from seat and the idle is still not right there is probably some water or a calcium build up in the bottom of the float bowl. If there is a build up of calcium the easiest way to remove it is with phosphoric acid, or get some aluminum wheel cleaner from one of the auto stores. I have even used muratic acid, you just have to be careful handling it. Check the fuel filters for water.
If there is no calcium then just use carburetor cleaner.

 

[Planet]

Cheers for all your input guys but as summer and Xmas are charging in I am just getting busier at work and am struggling to find time to work on this problem so with my days basking on the beach with a going boat draw nearer in my infinite wisdom just this time I admit defeat due to time constraints and are going to drop it if at my local merc dealer to get it right

once again thanks all