Carbs out of sync on Merc 60 outboard - help!

[JoeMan]

Picked up a nice condition '95 Merc 60 horse, has 3 carbs, each is one barrel. Previous owner told me he fiddled with the adjustment screws, and told me it's out of sync. He obviously should NOT have. It shakes and coughs a little when idling, and runs rough in general. What I've done thus far. New gas, new fuel filter, new plugs, cleaned carbs with Hog Wash carb cleaner until they sparkle in and out. Compression is good in all 3 cylinders, it runs cool. So my request of a Merc outboard expert (and I know you're here) is this. I want to make the carb adjustments myself, but have not done so before. I've made adjustments to my cars and lawn mowers, but I'm NOT assuming this is the same...so please be specific! There are 3 brass adjusting screws that I can see on the right side of each carb...a larger one towards the bottom, a smaller flat one which looks like it has a very narrow 'hole' in the center of it, and next to that one, another brass screw which protrudes out a bit and has a spring under the head. Which do I make adjustments to at low idle to sync, and which at higher idle? Tell me what to listen for, etc. You won't be held liable, I promise! I'm eager to get this thing running smoothly and learn something in the process. THANKS in advance!!!

 

[JoeMan]

Re: Carbs out of sync on Merc 60 outboard - help!

Any takers for some help/direction in this?

 

[Plainsman]

Re: Carbs out of sync on Merc 60 outboard - help!

Sorry I can't help you except to get the Merc manual for you motor.

I tried toPM you but couldn't.

 

[JoeMan]

Re: Carbs out of sync on Merc 60 outboard - help!

Thanks, I appreciate that...and while I know purchasing a manual for my motor would be a great thing...and I do plan to...can someone give me the typical routine for setting the idle and fuel mixture screws on a 3 carb Merc outboard? Or is it really that different from one to the next?

 

[Plainsman]

Re: Carbs out of sync on Merc 60 outboard - help!

I'm not familair with your motor, but for mine,I set mine lightly, then out 1 1/2 turns. Open some more out until it stumbles, the in until it stumbles, set in between.

 

[JoeMan]

Re: Carbs out of sync on Merc 60 outboard - help!

Eric,

Thanks. I am assuming we are talking only about the screw with the spring under the screw head? Should I leave the other 2 brass screws on each carb alone? Again, you may not be familiar with these.

Appreciated much.

 

[Plainsman]

Re: Carbs out of sync on Merc 60 outboard - help!

Yes that is correct.

 

[saumon]

Re: Carbs out of sync on Merc 60 outboard - help!

There are 3 brass adjusting screws that I can see on the right side of each carb...a larger one towards the bottom,

That's a plug that give access to the main jet inside, wich is fixed (can't be adjusted)

a smaller flat one which looks like it has a very narrow 'hole' in the center of it,

Vent, also fixed

and next to that one, another brass screw which protrudes out a bit and has a spring under the head.

Idle mixture screw. Setting is 1 1/4 to 1 3/4 turn out, like said before.

That is for the carbs idle setting, but maybe the previous owner also mess with the idle stop screw or throttle linkage, so you'll need to perform a link and sync as per the manual.