Zenith Carb Problem

kopeck · Dec 4, 2011

I just rebuilt my 52499d. The reason I rebuilt it is the tractor just wouldn't idle well.

I did what I usually do, soak it, use compressed air and carb cleaner spray on all the passages then put it all together according to spec.

On this carb the idle metering screw was pretty buggered up and needed to be replaced.

I installed it on my '47 A and now it runs worse then it did before hand. The weird thing is it runs best with the idle meter screw seated, I back it out a hair and the tractor really stumbles.

I checked for leaks with my propane torch and didn't turn up anything there, that and the throttle shaft was pretty snug.

It's running crappy at all engine speeds.

Any ideas?

K

Nebraska Cowman · Dec 4, 2011

did you take out the metering nozzle? It's maybe still plugged somewhere. Either that or there is a crack somewhere sucking air. Those can be hard to find. I have K5 Zenith I've had apart multiple times and can't make it work.

kopeck · Dec 4, 2011

(quoted from post at 16:46:29 12/04/11) did you take out the metering nozzle? It's maybe still plugged somewhere. Either that or there is a crack somewhere sucking air. Those can be hard to find. I have K5 Zenith I've had apart multiple times and can't make it work.

What do you mean by the metering nozzle? The short answer is yes, everything came out and was cleaned. The kit I used didn't include the idle jet or the idle meter screw, I used the old idle jet and got a new meter screw. BTW, the Tisco kit for this carb leaves something to be desired...

I have another 52499d that I had on the shelf. I pulled it apart to stick it in the carb dip and the little idle jet (maybe what you call the metering nozzle?) snapped on of it's ears off coming out. Now I've got to figure that out too. I wonder if they make easy outs that small?

I would like to fix this carb though. It seems like it's the same problem I had before but now it's worse. When I give it the throttle quickly it really pulses for a few seconds before calming down, the old governor rod really get's a work out for a moment.

Thanks,

K

Nebraska Cowman · Dec 4, 2011

metering nozzle = main jet

Try a left hand drill for your broken pieces. Eze-
outs don't work in soft metals because they force it
outward and tighter.

kopeck · Dec 4, 2011

(quoted from post at 18:49:39 12/04/11) metering nozzle = main jet

Try a left hand drill for your broken pieces. Eze-
outs don't work in soft metals because they force it
outward and tighter.

Gotcha.

I pulled it out and cleaned it up but I can do it again.

I guess it could be cracked, judging by how buggered up the metering screw it's been a problem for a while.

Oh, and good point on the easy out. I don't have a left hand bit that small, I'll have to try and find one, or a small set.

Thanks,

K

kopeck · Dec 10, 2011

So I took the whole thing back apart, sprayed down all the passage ways, hit them with the compressor, pulled the jets, made sure everything is clean, put it all back together and still the same thing.

So it has to be something in the casting right?

The only thing I can see that's not quite right is the gasket doesn't quite fit around the Venturi, I kind of just made it work, I guess I could have cut around it.

I have another carb in the dip right now. It's the one that the little idle jet broke in. I think I'll try just putting all the stuff from the bad one into this one. Pretty much everything that came out came out hard, main jet, vent, all of it.

I guess all those parts are NLA, which stinks. At this point I wouldn't mind building one with all new internals.

Also, under normal conditions with the metering screw bottomed the tractor should stall right, or at the very least run very poorly?

Thanks,

K

Zenith Carb Problem

kopeck

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Nebraska Cowman

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kopeck

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Nebraska Cowman

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kopeck

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kopeck

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