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Joined: Mar 2003
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Dear Expert Folks,

I have a '38 1/2 ton with a 216 and a Carter W1. If I let the vehicle sit for a few days and then try to start it, it floods. Gas all over the outside of the carb. The first few times this happened, I took the top off the carb expecting to find crud in the float needle / seat area. It was perfectly clean. Float is gas-tight, nothing sloshing around inside. I'm suspecting that when the gas evaporates from the float bowl, for some reason the float sticks in the 'down' position. I can't see anything that would cause this.

Further hints: I've replaced the carb for other reasons, and both the new carb and the old carb exhibited the same behavior. Also, if I smack the side of the carb with a wrench before I try to start it, sometimes this works.

Other than the flooding, it runs fine. Starts great, idles and drives smoothly. Once it's been started once, it's fine unless I let it sit for a few days.

Any ideas ?

Thanks in advance.

Alex Meade
Lexington, KY
[email protected]

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I had to install an adjustable fuel pressure regulator inline between the fuel pump and carb. My Rochester was constantly flooding. Today's fuel pumps put out to much pressure for many old carbs, try it at 2 pounds pressure. Hope this helps. Got the regulator at NAPA, but see them everywhere.


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JiMerit,

Thanks - good thought. This leads to another question, of course: The fuel pump is one of the ones that looks like the original except it has the extra vacuum pump to drive the wipers. Do these pumps run at higher pressure than the original ?

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The double-action pumps shouldn't run at any higher pressure than the single-action types. Try putting a pressure gauge on the carb inlet line, and run the engine with the line deadheaded into the gauge. It should run for a short time on the fuel in the float bowl. Most pumps I've checked that way run from 3 to 5 pounds, and hold the pressure for a short time after the engine is stopped. That shouldn't be enough to override a float if it's working properly. I'm guessing the float is hanging up on something inside the carb, and needs to be bent or adjusted to correct the hangup. See if the "float drop" setting is correct, the lower limit of the travel of the float. It's just as important as the upper limit adjustment!
Jerry


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I remember reading on a thread somewhere about making sure the sides of the float dont have any shiny marks on them indicating that it is hanging up on the gasket that might be protruding from the mating surfaces of the carb upper / lower body.

Also - put an inline filter between the pump and the carb, this solved this exact problem for me when the little pieces of crud would keep the needle from seating - the pieces were small enough to where they were not obvious but out of frustration I put the filter in and the problem immediately went away.

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Todays fuel (especially that containing alcohol) leaves a very sticky residue when it evaporates. The residue tends to be re-absorbed when fresh gasoline comes into the bowl.

The float could be temporarily sticking because of stickiness on the edge of the float arm where it contacts the float hanger. Make sure there is plenty of clearance at this point.

Jon.


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I would suggest you drive your truck more ofter to keep the carb full. I've got a tractor that does the same thing. When I start my tractor after it sits for a couple weeks you have to rap on the side of the carb right away or it will load up. When I use it on a regular basis, it works fine. I think Carbking nailed the diagnosis,
Scott


Scott Ward

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carb king and '48 are correct. Today's gas is so unstable that it gums up after only a few days. I have a Jeep and a JD 60 that have the same problem because I don't use them often enough.

Sometimes you can squirt spray can carb cleaner into the gas inlet of the carb and this helps for a few days.

The best thing is to take the carb bowl top off and dip the whole thing, float and all, into Berryman dip carb cleaner for a few minutes. This will clean almost any gum off andit will stay clean if you use it often. If you don't the problem will eventually return.


'31 Chevy 1 1/2 ton,
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Thanks to all who responded. Very helpful.

Alex


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