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Discussion Starter #1
I've got a 400 that's got some problems with flooding. I started it the other day it started flooding out. With engine off, I could see the fuel pump was pumping fuel into the carb. Getting past the needle valve. So, I had another carb for a 400 that I'd gone through and cleaned good, put it on, and it seemed to solve the issue. Ran it for about 30-45 minutes while I plowed my garden. Came back today and started it up to plow another garden. It started doing the same thing. I could see fuel pumping inside the carb. I closed the valve on the tank almost closed, and it seemed to run pretty good. Ran it for about 30-45 minuters again while plowing another garden.
Could I have two bad needle valves or could it be and issue with the fuel pump pressure?
 

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Sure sounds like the electric pump is overwhelming the float. Never had any of mine do that on a 400 but it's possible. Two carbs in a row doing it is pretty odd so it's seems like the pump is the villain. Better to deal with what's causing it but a workaround for a pump/float issue like that is a bypass line back to the tank. I have a 1 PSI Mr Gasket regulator stashed in my parts cabinet for problems like that too. It shouldn't be necessary for a stock 12V Facet pump on a K532 though.

Maybe Mr Wizard (Harold Goff) will see this and advise you better on this. If I were stupid rich I'd pay Harold to live next door to me.
 
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Typically, small pieces inside fuel hose flake off and jam needle partially open. Did you inspect seat on first carb?. Anytime a line is disturbed such as changing carbs, this flaking is very likely to happen, too. New TYGON fuel hose for modern fuel recommended. Place a small inline fuel filter just before carb good insurance. David
 

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A bad fuel pump or particles from deteriorating hoses are likely causes of fuel spillage into the carb as the float valve cannot control fuel flow. Also, is there any chance that you have stale or contaminated fuel? Stale ethanol-containing fuel that has partially evaporated is especially corrosive to carb components. Along with cleaning the second carb, was a new float valve installed, and was the float position adjusted? The float position does eventually change as the float adjusting tab and pivot wear.
Harold
 

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Discussion Starter #5
Fuel line is fairly new - replaced in the past couple years, as well as a fuel filter before the carb. Fuel had set all winter, but I ran all of it out and did put in fresh When it started this yesterday was fresh fuel.
On the other carb I just cleaned it out good. No kit. I looked at the other one and didn't see anything on the needle valve
 

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When replacing fuel hose, get hose that is listed as R9 or higher.
R6 hose gets deteriorated from the ethanol.
 

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Probably, if you have a kohler.
You should have an Onan p220 for an engine.
 

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Replacing the fuel hose on my 400 (which included a new pump) I put a filter between the tank and the pump and another between the pump and carb. I figured only a couple of bucks for some insurance. Might have been dumb but who’s going to know but me? Oh, wait....,
 

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I've got a 400, not a 420. It's got the Kohler K532
Don't quote me on this but I vaguely remember something about Deere putting Onans in some 400's. Possibly under warranty if a K532 went bang? Anybody know if that's right?

Replacing the fuel hose on my 400 (which included a new pump) I put a filter between the tank and the pump and another between the pump and carb. I figured only a couple of bucks for some insurance. Might have been dumb but who’s going to know but me? Oh, wait....,
Nothing wrong with that Jay. Only one per fuel line but I have automotive sized filters on my 400's. I put one on the first 400 I bought in '06 right after I got it. So far so good. Never had a problem with the other two either.
 

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I'll check on line and see what was used.
Would a cheap kit like this be fine? Carburetor Carb Repair Overhaul Rebuild Kit For Kohler K301 K321 K482 K532 K331 | eBay
I don't recall which vendor it was but I bought a new K532 carb online for $35 a few years ago and it works just fine. Wasn't much money to roll the dice on so I clicked Buy It Now. I rebuilt the carb I replaced and that cost about 2/3 as much as the new carb. I've also replaced the carbs on 12 HP and 14 HP Kohlers. They work fine too. No issues at all. Maybe I've just been lucky so your mileage may vary.

I also bought a new carb for a 23 HP Vanguard twin recently. I needed a complete new gasket set for the VG on my 420 and they were all included with a shiny new carb for $32 in total so I figured what the hell. Haven't tried it yet. After I bought it the 420 VG started behaving itself (surprise surprise). It's still really cold blooded though. Gonna try the new carb when time permits.

Some eBay links for new 400 carbs.


 

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New carb on the 532 I mentioned. Was actually 3 years ago according the image date.
265219
 
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I don't recall which vendor it was but I bought a new K532 carb online for $35 a few years ago and it works just fine. Wasn't much money to roll the dice on so I clicked Buy It Now. I rebuilt the carb I replaced and that cost about 2/3 as much as the new carb. I've also replaced the carbs on 12 HP and 14 HP Kohlers. They work fine too. No issues at all. Maybe I've just been lucky so your mileage may vary.

I also bought a new carb for a 23 HP Vanguard twin recently. I needed a complete new gasket set for the VG on my 420 and they were all included with a shiny new carb for $32 in total so I figured what the hell. Haven't tried it yet. After I bought it the 420 VG started behaving itself (surprise surprise). It's still really cold blooded though. Gonna try the new carb when time permits.

Some eBay links for new 400 carbs.


Or Carburetor for Kohler K482, K532 Engines 18 and 20 HP
 

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Discussion Starter #15
Very interesting. I actually ended up ordering a rebuild kit yesterday. I'd say those carbs, but would have thought for that price they were junk. I'd tried a cheap clone carb once on a truck of mine and it was worthless...haha. But, there's more going on in an automotive carb.
I'm going to try get a fuel pressure gauge on the pump to make sure it's not pumping too strong, put this rebuild kit in carb, and examine the fuel line and see what type it is The filter I have on it is a very large filter, not one of those little short ones.
 

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Sometimes a simple, red-neck gravity fuel supply is useful to distinguish carb internal vs. fuel pump pump problems. A 36" foot column of gasoline gives about 1 psi pressure. So, with 5-6 ft of 1/4" fuel line (or cheap but clean tygon hose for a one-time use) hooked to the carb and a small fuel can hung from a step ladder (or tree limb) you have a 2 psi fuel source much like a low pressure fuel pump. Be sure to cap the fuel line from the tractor's fuel pump before starting the tractor. In fact, if there is a problem with the needle valve or float, fuel leakage will probably be obvious even before the tractor is started. If there is no carb leakage, and the tractor runs fine, then the fuel pump is suspect.

On the subject of off-shore cheap replacement carbs, most WFM members seem to have positive experiences. A new carb for the price of a carb kit sure is enticing. I will not rule out buying one some day, but this story relates a negative experience. A buddy here locally put one on his poorly-running Onan P220 (JD 420) which also had an electric fuel pump upgrade. The engine ran better, but fuel was spilling out of the carb. Thinking the first electric fuel pump pressure was too high for the new carb, he replaced the electric fuel pump with a 1-2 psi pump, but the carb still flooded. It turns out that one side of the elaborately-soldered brass float in the new carb was full of fuel. Replacement with a plastic float from an Onan parts carb with proper adjustments gave a good-running engine.
Harold
 
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I'd tried a cheap clone carb once on a truck of mine and it was worthless...haha. But, there's more going on in an automotive carb.
That's a really good point. There's an old Scottish about complicating things that says, "The more they overtake the plumbing the easier it is to stop up the drain". A Kohler carb is pretty basic so there's less to go wrong with a new one.
 

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Words of wisdom as usual Mr Wizard. In a forum like this the ability to explain something is every bit as important as the knowledge itself.

Sometimes a simple, red-neck gravity fuel supply is useful to distinguish carb internal vs. fuel pump pump problems. A 36" foot column of gasoline gives about 1 psi pressure. So, with 5-6 ft of 1/4" fuel line (or cheap but clean tygon hose for a one-time use) hooked to the carb and a small fuel can hung from a step ladder (or tree limb) you have a 2 psi fuel source much like a low pressure fuel pump. Be sure to cap the fuel line from the tractor's fuel pump before starting the tractor. In fact, if there is a problem with the needle valve or float, fuel leakage will probably be obvious even before the tractor is started. If there is no carb leakage, and the tractor runs fine, then the fuel pump is suspect.

On the subject of off-shore cheap replacement carbs, most WFM members seem to have positive experiences. A new carb for the price of a carb kit sure is enticing. I will not rule out buying one some day, but this story relates a negative experience. A buddy here locally put one on his poorly-running Onan P220 (JD 420) which also had an electric fuel pump upgrade. The engine ran better, but fuel was spilling out of the carb. Thinking the first electric fuel pump pressure was too high for the new carb, he replaced the electric fuel pump with a 1-2 psi pump, but the carb still flooded. It turns out that one side of the elaborately-soldered brass float in the new carb was full of fuel. Replacement with a plastic float from an Onan parts carb with proper adjustments gave a good-running engine.
Harold
 

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On one occasion a 12 HP Kohler that had been on a Ford LT120 would not run right no matter what I did. It would race and sputter and start crappy. Eventually I put another used carb on it I had on the shelf. Exact same issues. So I rebuilt the first carb. No improvement. So I bought a cheap carb off eBay and that engine starts and runs fine now. Both used carbs must have had crap in them and the new one didn't. So sometimes a new carb can solve a problem just by being clean. The old carb is still on it in this pic but this is the engine I'm talking about. It was worth saving. It has a good 12V clutch on one end and a 1 1/8" shaft on the other. Kinda aggravating that they didn't go with a standard 1" size but I have a pulley hub that size that I can weld any size pulley on so it's fine.
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I certainly wouldn't bet the farm they're all good but I have enough confidence in the cheap carbs to have a new one for most engines I have. There was about 8 on the shelf in this pic and I've added a few more since. I even have one for my chainsaw. Some of them may end up not being good but I don't have much invested. Since I started buying the carbs I've spent way more on egg mcmuffins and hash browns. And look where they ended up.
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Since I started buying the carbs I've spent way more on egg mcmuffins and hash browns. And look where they ended up.
I expected to see a profile shot of a man with a large belly. But instead a shot of the workbench in nice and clean was a welcome sight.
 
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