I'll keep the story short and just say I concluded that I needed a new carb for my 4AO32 powered genset. Got a new carb in from Saturn and bam! - the engine starts first pull (repetitively) and runs like a dream ....... for 2 days. Then back to the no start doldrums. The engine does respond and run for 1-2 seconds to starting fluid so I'm convinced there's no ignition problem. My question: is 3 or 4 days soaked in gas (in the carb bowl) really enough to swell the float in a brand new carb (and thereby render the engine unable to start)? Thanx in advance!
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One more 4A032 carb float question
- Thread starter kgraeser
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I would lean more towards a fuel delivery problem. Use a bottle or gas can and gravity feed the carb to see if it will run. The fuel pump diaphrams are not long lasting.
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Hmm, I've had good luck with the Saturn carbs. Sorry, no help.
Thanx for your follow-up and I will try the gravity feed just to eliminate fuel delivery as a cause. FWIW, when I removed carb today I found intake manifold dry as a bone despite probably 20+ pulls. Does the float sticking problem always result in a flooded engine or can it also produce a fuel starved engine?
PeterD
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AFAIK, a stuck float can result in either condition, but usually it causes flooding. 
The problem may arise that should that be the problem, it is also possible that the various passages in the carburetor may also be clogged up, so even if you unstick the float, it may not run. (Only an experiment will tell for sure.)
The problem may arise that should that be the problem, it is also possible that the various passages in the carburetor may also be clogged up, so even if you unstick the float, it may not run. (Only an experiment will tell for sure.) 
Chief_919
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The floats in these carbs are very, very sensitive to ethanol in gas. Use gas with ethanol, and you will get that exact result.
ralbelt
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Did you replace the fuel line going to the carb. If not it is possible that some foreign material is sitting in the fuel inlet fitting and not passing fuel. If the needle is a little sticky and staying closed it is possible to wipe it on a very fine honing stone to clean it. Do not soak any rubber tipped needles or rubber seats in carb cleaner. Being a new carb you should not have to soak it.
Understand the ethanol sensitivity issue but if that is in fact my problem, I'm absolutely amazed that the swelling carb float occurred and incapacitated the engine in a period of less than four days of fuel exposure.
If a period of less than four days' exposure to fuel queers the carb, how can this engine ever be relied on to supply emergency power?
Seems like even precautionary measures like running all fuel out of engine at completion of use would still leave the float exposed to residual fuel (and susceptible to swelling).
If a period of less than four days' exposure to fuel queers the carb, how can this engine ever be relied on to supply emergency power?
Seems like even precautionary measures like running all fuel out of engine at completion of use would still leave the float exposed to residual fuel (and susceptible to swelling).
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I think the clearance on the float is too close. Iirc, they were troublesome with leaded fuel with varnish after long term storage.
I think I have read where people sanded the float to make it slightly smaller.
Ethanol fuel is wreaking havoc on all kinds of things. They have legislated the usefulness right out of gas and diesel. The guys passing laws have no idea what the real effects are.
I think I have read where people sanded the float to make it slightly smaller.
Ethanol fuel is wreaking havoc on all kinds of things. They have legislated the usefulness right out of gas and diesel. The guys passing laws have no idea what the real effects are.
ralbelt
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DH is right on with the ethanol problems.
Being in the aircooled industry when we pickle [prepare for long term storage] an engine first it is fully serviced then it is drained almost totally of fuel, add stabilizer, then run dry. We then add about a quart of off road fuel, no ethanol, with stabilizer and allow to run dry. Then the tank, fuel lines and carb are blow dried, then we inject marvel mystery oil into the carb, fuel lines and tank. A small amount on top of piston is also added.
Yes it will smoke for a few minutes when it restarts 1,2,5,10 years down the road but it will start.
This past week with the after effects of Irene the only thing we did was generator repairs. Every one had fuel related problems and all said ran when parked.
Being in the aircooled industry when we pickle [prepare for long term storage] an engine first it is fully serviced then it is drained almost totally of fuel, add stabilizer, then run dry. We then add about a quart of off road fuel, no ethanol, with stabilizer and allow to run dry. Then the tank, fuel lines and carb are blow dried, then we inject marvel mystery oil into the carb, fuel lines and tank. A small amount on top of piston is also added.
Yes it will smoke for a few minutes when it restarts 1,2,5,10 years down the road but it will start.
This past week with the after effects of Irene the only thing we did was generator repairs. Every one had fuel related problems and all said ran when parked.
Thanx guys and I apologize for going into "whine" mode on my earlier post. I had a lot of pride in my machine as compared to neighbors' Chinese imports and it let me down terribly during Irene. Even with that, I'm still trying to get it running reliably and sonuvab#@%& won't cooperate. Really frustrating but I'm not giving up.
Chief_919
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Yep. Sucks doesn't it.
Keep in mind when these engines were made, there was no ethanol in gas, so they were not desigend to handle it.
Sta-Bil Marine Fuel Treatment is claimed to counteract the negative effects of ethanol in small engines like this. My suggestion is to traet all fuel you plan to use with the generator.
On the topic of 4A032 storage and removing fuel from float bowl to avoid carb float swelling - what do you all think about evacuating residual fuel from carb/float bowl using a Mity-vac or similar suction device (following running majority of fuel out of engine)?
Chief_919
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It may help, but the float will still absorb the ethanol during use. You are just delaying the inevitable.
The only solution is to either use ethanol free gas or use a treatment to remove the ethanol before you use it. Anything esle is a band aid.
You can usually find stations advertising ethanol free gas anywhere near a popular boating location, as ethanol is a big problem for outboard engines.
Here is a website listing stations that carry ethanol free gas.
Ethanol-free gas stations in the U.S. and Canada
mdlbldrmatt135
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I've modified an all Brass float and have it installed in a Spare Carb. I'm hoping to try running it here sometime, if free time ever comes back around.
68impalass
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I also modified a brass float and a plastic one. It seems the floats do not float well with ethanol in the gas.
m139h2otruck
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I have had good luck running the fuel out of the carb on shutdown with both the 2a016 and 4a032 engines. Never had a problem while they were running (4 cylinder unit ran for over 6 days a couple of years ago in an ice storm). Also, have added non-detergent oil to the gas @ about a quart to 10-15 gallons which seems to help some too.