Rebuilding Zenith or Buy Rebuilt

marcusmerritt · Oct 18, 2017

Ford 2000; 3 cyl. gas; 4/1 trans....I'm having problems getting my tractor started and, among other things, am considering rebuilding the carb but have never had any kind of good luck with carbs on mowers or small equipment. Is the rebuild process for the Zenith carb fairly idiot proof, fairly simple or am I better off buying a rebuilt carb from this site? I have a large ultrasonic cleaner. Would that be the best way to clean the parts? Can I assume the parts kits on this site are as good an any other source? Is there a step by step instruction or video that would be useful?

Thanks.

Tim PloughNman Daley RIP · Oct 20, 2017

I'd do a systematic, root cause determination before buying any new parts first of all. Spark, fuel, and compression are the essential elements needed to run. Concentrate on the first two for now. I only worked on one Zenith carb before and it was junk, but that is my opinion. I prefer the original Marvel-Schebler carbs. They were built robust, meant to be rebuilt over and over. Before pulling carb, verify fuel flow is good, verify you have good spark. We could use a bit more info here...6-volt or 12-volt? Doe sit start now or just won't turn over? Condition of battery -meaning does it sustain a charge under load, and don't answer with "...it was purchased new two years ago..." Cheap batteries don't last long. I recently worked on a customers Massey-Ferguson which he swore wasn't the battery because he, "...just bought it new last year...". Take it to your trusty local starter/alternator shop and he will bench test with the proper equipment. We'll go from there, and YES it does matter where you buy parts from.

Tim Daley(MI)

Royse · Oct 20, 2017

I would check for quality spark and good fuel flow through the
carb as Tim mentioned. I would also check compression if hard
starting is the main complaint. All are free to test.

If you do decide to rebuild the carb and find a place to buy a complete
rebuild kit for that Zenith I'd sure like to know where you found it.
Most of the kits for those just come with gaskets, seals and a new
needle valve and seat. Many times, that's enough, but not always.
I modified Marvel Schebler jets to fit my brother's Zenith.
Couldn't buy them anywhere I looked. Two years now, so far, so good.

The most important thing when rebuilding is to clean it thoroughly.
Dirt, dust, rust from gas cans/gas tank, etc. gets lodged in the
small passages and hidden behind the jets. It has to be spotless.

59casey · Oct 20, 2017

I used a kit I bought online for my Ford 5000 Zenith and it has been easy and flawless after that!

TinCan · Oct 21, 2017

I just rebuilt a Zenith on a Case Dozer. It had been sitting a long time with ethanol gas in it (bad stuff!). It wouldn't run more then a few seconds. It was easy to rebuild. I took all jets/everything out, cleaned everything from behind jets, and plugs. Made sure the float sealed off, set the float level, and reassembled it. started with the jets turned out 1 1/2 turns out, and straight regular gas, then started it, and then fine tuned the jets, and now it now runs great!

I would think replacing the jets would be a odd thing to have to do, under normal rebuilding. Just don't mar them with the screwdriver taking them out.

Pat

marcusmerritt · Oct 21, 2017

Thanks for everyone's comments. I'm still working on getting the tractor to start and thought a carb rebuild would be good to do once I have my hands greasy. I have no idea when it was last cleaned or rebuilt. It's got a lot of varnish on the bottom, I guess where it has leaked over the years. It tends to drip after trying to start it and I understand that is typical for these updraft carbs. However, it does not drip on a regular basis, just when I'm trying to start it will it drip a bit and then stop.

On another forum regarding Ford carbs, someone suggested gently running the jets in all the way and them backing them out to their original opening. The idea was to push or crush any debris in the orifice so that they would be clear. Any validity to this action if done gently? Thanks.

Royse · Oct 21, 2017

"running the jets in all the way and them backing them out to their original opening."

What you would be turning is the adjustment needles.
The jets are inside the carb and on most carbs, including the Ford
carbs, they are not adjustable. They are a screwed-in brass orifice.

Personally, I would prefer cleaning it over trying to shove dirt in
further. Even if done gently. That is how they are adjusted though.
Gently seat the needle (all the way in) then back it out to the
recommended starting position. Usually 1 1/2 turn on the main works.
Then adjust as needed to get it dialed in and the engine running
correctly. It usually takes a few times.

marcusmerritt · Oct 21, 2017

Ah...thanks for the correction. As you might suspect my experience with carbs is very limited. I'm gonna try to get it cranked this week as I need to use my scarifying implement to try to excavate some roots from trees we cut down a couple years ago. This is a fantastic forum and all input is appreciated.

Royse · Oct 21, 2017

It's a common terminology mix up, not a big deal.
It does make a difference though when we're "talking" about what to adjust or replace on a forum.

I rebuild a lot of Marvel Scheblers for fellow forum members.
I've done quite a few Zeniths, IH, Holleys etc. too.
But I don't want to rebuild them for the 3 cylinder tractors, so no sales pitch here!
On the other hand, I would be willing to help you do it. Email should be open via YT.

marcusmerritt · Oct 21, 2017

Royse....your offer is very generous and one I may need to take you up on. Probably, once I've got a rebuild under my belt, the next one may not give me the jitters. Many thanks.

Rebuilding Zenith or Buy Rebuilt

marcusmerritt

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Tim PloughNman Daley RIP

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Royse

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59casey

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TinCan

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marcusmerritt

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Royse

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marcusmerritt

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Royse

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marcusmerritt

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