4A032 Carburator -- rebuild or replace?

[jas67]

I have three APU/Gensets with the 4A032 engine on them. I'd like to get these running, but would assume the carbs are probably all gummed up from sitting. Are rebuild kits available for these, or is it just best to replace the whole carb?

Thanks,
Jay

 

[jbk]

saturn surplus on the web carbs go for about 40,00

 

[carey clarkson]

4A032 carb rebuild

The 4A032 carbs are very easy to fix if you take your time. I couldn't find the bowl gasket however if you go by your auto parts store you can buy a whole roll of fuel proof gasket material for about $5.00! Just turn carb bowl upside down on the gasket material and trace the pattern and then cut out with an exacto knife. Very simple! Remove the float by removing the brass bar directly behind the float and lift up on the float to remove. Remove the large brass screw on the carb bowl and remove the valve seat needle assembly (spring attached) and dip carb in carb cleaner for several hours and unthread the main jet with screw driver to ensure it is clean and free from gunk. Use carb cleaner to spray all orifices from inside out. Reinstall needle assembly, main jet, bowl and your done. I have "refurbished" 5 or six of these carbs and they work good as new.

 

[nathanto]

Does anyone know who makes The carb? Is There a replacement for the float? I have mine running propane, but would like to run gasoline.

 

[Keith_J]

The carb is a military standard model, since its SMR code is PAOZZ, it is not deemed rebuildable so the federal supply system never had overhaul kits.

But surely there must be a source for parts, I have yet to find any. Will update if I find anything. What I need most is the float valve needle seat.

 

[Keith_J]

Necessity is the mother of all inventions.. I have a set of Viton o-rings from Horrible Freight Tool, the smallest o-ring is A005, it is just a little too large to fit into the float valve to replace the hard/old one that was leaking. But it fit over a 1/8" Dremel bit shaft, then turning at 8-10 k RPM, I gently turned the OD to remove the outer round cross section, leaving the inner round profile. It snugly fit into the recess of the float valve seat. As second A007 o-ring, without modification, was placed in the carb to further seal the seat.

Testing with Coleman fuel filling the bowl and 6 PSI air pressure on the fuel inlet proved no more leakage . The old seat would bubble like a hot tub full of Mr. Taggert's band of toughies.

The float moves fine and most importantly, floats. I will just run ethanol-free gasoline in it. I remove the ethanol with ordinary water, letting it settle out and removing the sediment (1% water by volume, shake and let sit overnight). Do this three times and you get 99% of the ethanol out. Then let it sit overnight with a drying agent (epsom salt, baked in an oven at 350 F for 4 hours) and decant again. No need to filter if you are careful. No, you CANNOT drink the ethanol-water you recover as it is still rich in gasoline. But it is good for starting fires as it comes out at 70% (140 proof).

 

[Keith_J]

YES, it WORKS!!! Made a quart of de-ethanoled gasoline and fired it up. Since the air filter is toast (literally), I primed it there with a tablespoon of gas on the filter element. One pull, then the pump filled the bowl and then governor kicked in. 3600 RPM.

Found out the manifold on the preheater side is leaking, BAD. That is why the air filter is toast, even without the preheater valve open, the filter overheats.

No biggie, saved a pantload on the carb, the filters, manifold, gaskets and other stuff to get it going fully are far cheaper.