Zenith Carb (12225) replacement jets?

fnkfab · May 4, 2020

Hi, I tore apart my zenith carb (12225). This thing was pretty nasty inside, especially with what appeared to be uncured or reacted RTV that was used to seal
it. Attached photos are of it cleaned up a bit (still a ways to go).

The float appears to have gas in the pontoons (which explains some issues i had with the tractor pointed up hill) so i plan to replace that.

I've got a rebuild kit from YT, but it doesn't contain the two little jets in the castings. Also whoever rebuilt this stripped them pretty badly. I'm planning
to drill out, remove, and replace-- but i cannot find these in any of the rebuild kits anywhere.

Anyone know what PN these little jets are? And where i can find them?

coshoo · May 4, 2020

Try this guy- Mike's Carburetor Parts, 888 689-9758 or email [email protected]

Mark-Ia · May 4, 2020

Heat the jets and the area around them with a torch,let them cool and they will screw out easily.

Crazy Horse · May 4, 2020

In addition to Mark's comment here, don't be afraid to sacrifice a slot-headed screwdriver and file the end down so that it fits SNUGLY in what remains of those slots in the jets. No question though, heat is the ultimate solution. Other than being messed up a bit, what makes you think they need to be replaced? Easier to clean the channels inside yes but it can be cleaned without removing those jets. I would say that drilling is a risky maneuver.

fnkfab · May 4, 2020

(quoted from post at 12:02:01 05/04/20) In addition to Mark's comment here, don't be afraid to sacrifice a slot-headed screwdriver and file the end down so that it fits SNUGLY in what remains of those slots in the jets. No question though, heat is the ultimate solution. Other than being messed up a bit, what makes you think they need to be replaced? Easier to clean the channels inside yes but it can be cleaned without removing those jets. I would say that drilling is a risky maneuver.

Good stuff guys. Kuhns in NY is shipping me out some jets shortly.

Would you not remove these jets to clean them? It just seemed obvious to me that that would be the happy path. What's the alternative, just point the carb cleaner nozzle in and spray until things seem to flow OK?

Steve@Advance · May 4, 2020

I would not risk trying to remove them.

Especially if you can't read the numbers.

I never even try to get them out, just be sure they are really clean. Spray cleaner will not remove dried ethanol residue. It has to be scraped out with a stiff wire, a torch tip cleaner, or the smooth end of a drill bit.

You can buy a set of jet drills at a reasonable price. They are good for measuring and cleaning jets, and can be used to drill jets in a controlled manner.

Mike(NEOhio) · May 4, 2020

I've had success getting them out. Heat, propane torch is all you need, till it starts to smoke a bit. I usually hold them down on a wood bench, sometimes clamp if I have to. A GOOD screwdriver that fits the whole slot. I apply chin pressure and with both hands slowly increase the torque and they usually give. If it feels like it's twisting out of the slot stop and reset the screwdriver. Search the carb brand and number. Mike as said is good and you'll find several more.

gene bender · May 5, 2020

I have never heard about dried dried ethanol i have been using that fuel here in Iowa since it started with never any carb problems with my As and Bs they set all winter in a dirt floor shed and will start rite up in the spring batts can be down sometimes but never a carb issue. Our gas suppliers must be special because of the problems i hear about the 10% mix as we have been using it since the 70s

fnkfab · May 8, 2020

(quoted from post at 18:56:04 05/04/20) I've had success getting them out. Heat, propane torch is all you need, till it starts to smoke a bit. I usually hold them down on a wood bench, sometimes clamp if I have to. A GOOD screwdriver that fits the whole slot. I apply chin pressure and with both hands slowly increase the torque and they usually give. If it feels like it's twisting out of the slot stop and reset the screwdriver. Search the carb brand and number. Mike as said is good and you'll find several more.

This worked pretty good until it didn't. Maybe you've got more years on you or just better hands. My jets both came out a 1/2 turn or so and then the face with the screw driver (that i customized) more or less exploded. I reverse drilled-- nothing-- then put an EZ out in. I got the two jets out but with some thread damage. My new jets arrive tomorrow. I'll measure the threads and order some taps/helicoils, and go from there.

One question though-- those jets were stripped to heck before i tried removing them. Do they typically go in easy? I wonder if the previous owner stripped them trying to remove or on re-install?

fnkfab · May 12, 2020

Updating for posterity.

I was able to remove the jets by drilling out. It was a little messy so i had to retap the holes. New jets went in just fine. I ordered them from Kuhn's tractor in NY.

This thing was super nasty inside. I'm pretty happy I tore it out.

Jet drills sound like a good idea though.

The main jet came out easy-peasy, not sure why.

Anyways, the reason i tore it down was i suspected a leaky float---and i was right. The float was full of fluid. Symptoms were fuel starving when pointed up hill and leaking gas when sitting.

New float, new jets, a basic rebuild kit, and a wire wheel on a dremel.. this thing went back together and my tractor fired right up and drove around for a half hour with no issues.

Thanks all for the help/wisdom/encouragement.

Zenith Carb (12225) replacement jets?

fnkfab

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coshoo

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Mark-Ia

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Crazy Horse

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fnkfab

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Steve@Advance

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Mike(NEOhio)

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gene bender

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fnkfab

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fnkfab

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