Carburetor question for a 1986 Mercruiser 3.0 Litre

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My service manual references two mixture screws. I can only see one. Should I be seeing two? I have uploaded a couple pictures.


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[alldodge]

The tag on the carb says its for a 120 and 140 motor. The 1389-9350 is for the 2.5L an some 3.0 but not in 1986. I'm seeing the 3.0 came out in 1987

In any case the single adjustment screw is not an issue for the motor

http://www.mercruiserparts.com/bam/subassembly/30893/963/140

 

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Thanks for the help>

 

[Scott06]

Single idle adjustment screw means you have a Mercarb vs the Rochester 2 bbl service manual you are looking at. Very similar carbs as they have a common lineage and the single idle mix screw works the same . Float levels may be different so if you are doing a full carb service might want to find the right manual. This show set up specs

http://www.carburetor-parts.com/assets/images/K529.pdf