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Is this a good deal?
- Thread starter John S
- Start date
The float is fine, I’ve submersed it in water for an hour and it’s not leaking. The tank has been cleaned and sealed inside. The sediment bowl is new and the gas in there is crystal clear. So it’s got to be that needle and seat. Maybe the float level? I guess my next move is to get a rebuild kit and swap them out. Do I go to the local Case/IH dealer or is there a better source online? I’ve read about the Kohler trick on the Cubs but I don’t think that will work for a Farmall A, will it?
OK now I’m at wits end, I installed the new IH needle & seat and its still dripping? I started it up, backed it out of the garage and let it run for half an hour. Ran fine and didn’t die this time. Pulled it back in to the garage less then a minute later not dripping but a steady stream started to flow from the drip hole this time? What the heck is going on? I ordered a repair manual today but other than the float level being wrong I’m out of ideas. Does anybody know anything about these new reproduction Marvel carburetors? There is one on ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... %3AIT&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... %3AIT&rd=1
A
Anonymous
Guest
John.
I only ever have a slow drip on mine when the A isn't running, so I've not had mine apart, however:
If they're at all like the carbs on the early M's .... there is a little tang that pushes the needle valve back up when the float rises. this can get bent over time. try bending it gently in the direction that would push the needle valve up further into its seat, and see if that does the trick.
The way they get bent is....a piece of crud holds the needle valve down away from its seat, the float rises higher and higher, and puts pressure on the tang...over time, the tang bends.
I know that there's a precise level for setting the float by bending the tang, but from my experience, just enough to stop leaking is a pretty good setting.
Just a suggestion, and if I'm way off base, the experts will correct me, I'm sure.
Tom
I only ever have a slow drip on mine when the A isn't running, so I've not had mine apart, however:
If they're at all like the carbs on the early M's .... there is a little tang that pushes the needle valve back up when the float rises. this can get bent over time. try bending it gently in the direction that would push the needle valve up further into its seat, and see if that does the trick.
The way they get bent is....a piece of crud holds the needle valve down away from its seat, the float rises higher and higher, and puts pressure on the tang...over time, the tang bends.
I know that there's a precise level for setting the float by bending the tang, but from my experience, just enough to stop leaking is a pretty good setting.
Just a suggestion, and if I'm way off base, the experts will correct me, I'm sure.
Tom
Lurker Carl
501 Club
John, this is a tricky problem to diagnose from a distance. Here's some more things you can check. That eBay carburetor looks like a Zenith - the seller's lousy picture makes it hard to tell.
If your particular carburetor is cast aluminum, make sure the float isn't contacting the bowl casting due to someone beating on the carburetor to stop the leak. Check the castings carefully for cracks, pinholes or other defects.
Having a sealed tank doesn't mean the fuel is clean. Fuel can be contaminated by a deteriorating fuel line.
Shake the float by a good hearing ear and you'll hear liquid splashing inside if the float is a leaker. Immersing the float in water will not determine if it's leaking unless the water is HOT and the float is cool. That's the only time bubbles come out of a leaking float, the bubbles are small and come out slowly. Turn the float over in the water so you'll see the air bubbles from all angles, checking both pontoons.
One other thing to remember - the tractor has a gravity feed fuel system. If you have fuel in the tank, gravity keeps it pressurized whether the tractor is running or parked. Every little crack or crevice that isn't sealed will let fuel come on through. Check the needle cage seat for any corrosion or gouges that could be potential gas leakers.
If your particular carburetor is cast aluminum, make sure the float isn't contacting the bowl casting due to someone beating on the carburetor to stop the leak. Check the castings carefully for cracks, pinholes or other defects.
Having a sealed tank doesn't mean the fuel is clean. Fuel can be contaminated by a deteriorating fuel line.
Shake the float by a good hearing ear and you'll hear liquid splashing inside if the float is a leaker. Immersing the float in water will not determine if it's leaking unless the water is HOT and the float is cool. That's the only time bubbles come out of a leaking float, the bubbles are small and come out slowly. Turn the float over in the water so you'll see the air bubbles from all angles, checking both pontoons.
One other thing to remember - the tractor has a gravity feed fuel system. If you have fuel in the tank, gravity keeps it pressurized whether the tractor is running or parked. Every little crack or crevice that isn't sealed will let fuel come on through. Check the needle cage seat for any corrosion or gouges that could be potential gas leakers.
'Country' Elliott
501 Club
John...You might try adding some SEAFOAM (available at NAPA stores) to your gas tank (about 2 to 3 oz. of Seafoam per tank full). Always be sure when your "A" is not running and parked to turn off the gas at the shutoff on the sediment bowl. This will keep any gas from running from your gas tank down into the carburetor. :wink:
From what you describe...I'd say your carburetor float is NOT damaged, but is hanging up somewhere on the inside of the carb. It can be something as simple as a gasket that's too large and blocking the float from returning to it's fully closed position. :wink:
From what you describe...I'd say your carburetor float is NOT damaged, but is hanging up somewhere on the inside of the carb. It can be something as simple as a gasket that's too large and blocking the float from returning to it's fully closed position. :wink: