Warped carburetor

holt2ton · Oct 12, 2016

I have a '59 Cockshutt 540 with a Zenith carburetor. The tractor would only run with the choke mostly on. So I bought a rebuild kit and while putting it all back together I noticed that the top half of the carb and the bowl half are warped. What are my choices? When it was running with the choke pulled I sprayed the entire outside of the carb with cleaner but got no change in RPM? So what else could be causing the choke issue? I'm lost!!

Steve@Advance · Oct 12, 2016

Where the top and bowl seal together with a gasket, there is a small passage that supplies fuel to the idle and mid-range circuits. If that is leaking, it will cause poor or no idle, and a dead spot just off idle before the main circuit comes in. Also check the gasket, there may be more than one gasket in a kit. Be sure all the holes line up.

It will be difficult to do much with the top piece because of the float hanger protruding down, but the bottom can be lapped flat with a sheet of sand paper and a flat surface. That may be enough to get it to seal as the gasket is quite thick.

Also be sure the venturi is installed properly and fully seated before tightening the screws. That is probably how it got warped.

holt2ton · Oct 12, 2016

Thanks for the info. I lapped the bowl half on surface plate with some sandpaper. Almost all of the gap is closed off now. I'm going to re-clean everything and see what happens. Any idea on the float height setting?

Steve@Advance · Oct 12, 2016

I don't have the specs on the float level, but generally with the upper housing held upside down, the top of the float should be parallel to the gasket surface, maybe slightly higher at the toe end. If there is a stain line where it has been siting in the gas, try to get that parallel with the gasket surface.

Bhunt · Oct 12, 2016

(quoted from post at 14:43:59 10/12/16) Thanks for the info. I lapped the bowl half on surface plate with some sandpaper. Almost all of the gap is closed off now. I'm going to re-clean everything and see what happens. Any idea on the float height setting?

you should have a brass tag round riveted on the car top section you need to look for that number there may be a number on the very outside edge of the circle and a number on the inside of the circle you need that number to know what carb you have for the float height. The number on the inside would be the zenith number and more readily helpful the outside may have the tractor manufactures number I may have that setting if you have that number. As Steve noted most but not all are set holding upside down and making it level. If you have a new gasket kit it should have the float setting in it the instructions.
Best of luck Byron

holt2ton · Oct 12, 2016

It's a Zenith 112262. The tractor is my son's, I'm helping him on this one. He accidentally threw out the handy-dandy L-shaped scale for float setting!! Ah...kids!!

Bhunt · Oct 12, 2016

Sorry I have nothing with that number

Byron

Moonlite37 · Oct 12, 2016

When I worked in an Allis Chalmers dealer shop we repaired all makes, WE set all updraft carburetor floats with turning them upside down and sighting for level. Never knew it to fail.

holt2ton · Oct 12, 2016

Running good!! She fired right off and only took a bit of adjusting to get it purring along. Thanks to all for your your replies and tips!

Warped carburetor

holt2ton

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Steve@Advance

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Steve@Advance

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Bhunt

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Moonlite37

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