Carburetor Question - 1988 Mercury 8HP

[97mirage]

Can anyone please confirm that Mercury has changed the carburetor slightly on my 1988 Mercury 8HP outboard (serial number OB366443)?

The original carburetor has "WMC 18B" engraved on the side so I ordered a new WMC 18B carb from MarineEngine.com (using their online parts guide). According to their website, the carburetor has been upgraded five times and the new model appears to include an additional adjustment screw located on the throttle shaft assembly (see the white plastic piece in the attached pictures). However, my original carb does not have this adjustment screw (see the other picture).

So, my question is this: Is the adjustment screw something that Mercury added onto newer model carbs and I have ordered the correct carburetor?

Any help would be appreciated.

Thanks.

488058488059

[25two.stroke]

yes that is correct. They changed things in the casting to: having to do with the bleed line routing and fuel pump pulse.
You can easily change out the butterfly and shaft if you want to put the old style (no screw) back in. If you look at the fuel pump cover there the new carb and old carb are different.

If you have questions on little motors you can call me, Jacob 510-418-4911. I am always happy to help if I can...

[97mirage]

Jacob:

Thank you very much for this information. I have been "monitoring" your responses to all the technical posts. You seem very knowledgeable and have been very helpful to a lot of folks here.

Thanks for your contributions. If I get hung up, I will give you a call.

Thanks again.

97mirage (Brian)

[25two.stroke]

Jacob:

Thank you very much for this information. I have been "monitoring" your responses to all the technical posts. You seem very knowledgeable and have been very helpful to a lot of folks here.

Thanks for your contributions. If I get hung up, I will give you a call.

Thanks again.

97mirage (Brian)

Ya just make sure the mating surface and gasket in the intake match. If the accelerator pump outlet and the fuel pump pulse holes match the gasket and the intake manifold then you are all good...

And just fyi, change out or really closely inspect the bleed line under the carb. I see pin holes in that where it sides on the carb ALL THE TIME. People rebuild and rebuid their carbs trying to get it to idle right and can't, they bring it to me and I have it fixed in 5 min witrh a new line... the same line they have been touching every time they rebuild the carb but never notice it is cracked or leaks air.

[97mirage]

I know exactly what you mean about the small length of bleed line under the carb. I change it every other season. I have found tiny tears where it slips onto the nipple so you are right on the money. Thanks again!