Help-Idle mixture screw location?

revitup

Cadet
Joined
Mar 19, 2008
Messages
9
Hi guys, I need help locating the idle mixture screw on my 88 Mariner 175. I have a SELOC manual and still can't seem to locate it. Motor seems to be running rich. Thanks for the help.
 
Joined
Mar 10, 2009
Messages
27
Re: Help-Idle mixture screw location?

If you have the crabs I think you do there us no screw. The idle mix is controlled by jets. My 150 also runs rich at idle with the correct jets in it. I'm nervous about leaning it out. May do it though can smell fuel in the exhaust and the carbs are freshly rebuilt.
 

bob1340

Petty Officer 1st Class
Joined
Jun 12, 2010
Messages
287
Re: Help-Idle mixture screw location?

I am going out on a limb as I don't know your motor, but in most cases the idle mixture screw is located at the top of the carb throat. On my little 7.5 it is recessed into the face of the throat. If the motor is running rich at speed this has no effect on it.
 
Joined
Mar 10, 2009
Messages
27
Re: Help-Idle mixture screw location?

Naah no screw on these (thanks epa). There should be a brass plug on the top on both sides of the carbs. Behind that your idle jets.
 
Joined
Mar 10, 2009
Messages
27
Re: Help-Idle mixture screw location?

Should be the same type. I have a service manual and it covers about 6 models over 10 years. Merc didn't like to fix what wasn't broke.
 

revitup

Cadet
Joined
Mar 19, 2008
Messages
9
Re: Help-Idle mixture screw location?

yep. I have 3 carbs. I guess there isn't a idle mixture screw. Thanks for the help.
 
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