1997 Mercury 125 2X2 - Rejetting / Recarb ?

So I was running down the river last week and the motor stopped on me. I coasted and attempted to restart. The engine has seized. Now I get to rebuild, which I am looking forward to. I have a question

2X2 Design - From what I hear this was only used on a few models. Technology relies on 2 carbs not having idle jets and thus not active until enough pressure is exerted on the fuel system to push fuel past the drive jets.
I have heard great things about the Merc 125s and have had many other Mercs with no issues.


Has anyone heard of rejetting the carbs so that all of the cylinders fire during all speeds. I use my boat a few times a month and the fuel consumption is not my concern. I want an engine that idles smoothly and does not lean out for fuel savings.

Can I rejet or has anyone heard of using a carb from another 125 of the same era without the 2x2?

Thanks for your advice.

I know of several mechanic's that have tried this but to no avail, the engine will not idle and shakes itsself apart, thats why Merc designed it this way. Rejetting it will not make it run on 4 as carb is different .....

faztbullet said:

I know of several mechanic's that have tried this but to no avail, the engine will not idle and shakes itsself apart, thats why Merc designed it this way. Rejetting it will not make it run on 4 as carb is different .....

Click to expand...

Thanks but that does not make a whole lot of sense. I asked if the recarbing was an option.

Shake itself apart, Do you mean when all 4 cylinders are active. That is what happens when the motor runs above the idle jet threshold.

"That is why Mercury designed it this way".....what are you talking about? Mercury designs engines to shake apart when all 4 cylinders are firing. Cmon really.Anyone else?

merc. designed it to run on the top two cylinders under 1850 RPM. all 4 plugs spark , just not enough fuel to ignite. call merc. and talk to the engineering division...would like to know what they say.

i was going to buy a 4 cylinder merc 100 hp in the 1995 time frame..i was told that merc could not get them to idle right and went to this running on two at low speed as a fix....i opted out and bought a 90 evinrude instead...when and if you talk to merc engineering ask them why most mercs (even the new ones) rattle around like a can of marbles when in gear just at or above idle..i have a camp with about a ten minute idle speed zone...i can tell it a merc coming before they come around the bend where i can see them...i am now running a 4 cylinder 60 merc 4 cycle efi and it does it but i am not worried about it...