Carb cleaning; must I remove the orifice plugs?

[Alan]

Hello to all;
I’m currently cleaning the carb, (model E, type II, w/ fixed high speed jets) from my ’67 80 HP OMC. For like the fifth time. Carb kit installed, new needle and seat; NOS float on the way. I’ve pulled the welch plugs, (again).

In looking over the exploded drawing, I spotted something I hadn’t noticed before; the bowl drain screws have an, "orifice plug" behind ’em. (part # 309415). From what little I see, these have a hole in them, and look more like jets than plugs. #36 in the pic below.

Do I need to unscrew these? They’re a ways down the drain plug holes, and I’d need a narrow screwdriver or small jet tool, but I’ll do what needs to be done, if necessary.

After soaking in a Pine Sol solution, and hitting it w/ carb cleaner and compressed air, it finally coughed up several chunks of what appears to be silicone sealant, (which I never, ever use on carbs), so I’m glad to get those out. I’ll keep soaking it, (in a covered container, in the sun; it’ll be 108 degrees in the shade today), and using cleaner and compressed air, ’til I get no more chunks. These have emerged after a multitude of cleanings w/ spray, and a previous three-day soak in lacquer thinner. Maybe Pine Sol will fix a long-standing problem.

I’ll appreciate any info or opinions.
Many thanks;
Alan

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[garry-in-michigan]

I usually just remove the (38) Drain plug screw and use a pipe cleaner dipped in carburetor cleaner to run through the fixed jet orifice. Do not use anything that could change the diameter as that would change the high speed mixture. As such they must be absolutely clean. . . 😉

[Alan]

Many thanks Garry!
So, these are jets; very good to know.
I’ll clean ’em carefully w/ pipe cleaners. I fear there may more sealant chunks in there; I’m just kinda shocked to see them emerge, after so many other attempts at cleaning.
Appreciated;
Alan

[frankr]

Under the circumstances (silicone chunks), I think I would remove them if they will come out without a lot of grief. You are supposed to use a special screwdriver with parallel sides. A regular screwdriver tends to spread the soft brass slot, making them tighter than ever.

But if you feel you can get all the junk out without removing them, that is fine also.

Yes, those are metering jets and as such are highly precision holes through them.

[Author]

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