Just Another Carb Issue

[goodnigh]

The carb is a Holley 0-86770 and has an externally adjustable float

with site windows. The carb has been on the car for 2 1/2 years.

The car began to stall when sitting in traffic. Driving at speed was no

problem. I checked the site window and the fuel level was not

visible, meaning it topped out. I readjusted so the level was at half

in the window. Ran the engine at idle for five minutes no change,

then the level began to creep up again till it flooded the engine.

Readjusted the float level and same problem. If there was debris

in the needle valve you would think the level would rise when you

started the engine and not five minutes later. Found an easy

solution to the problem, bought another carb. We will take this one

apart and see what went wrong.

mike

 

[Totalled]

Ethanol gas corroded the needle and seat. You need to use an additive with every tank, or carbs suffer in short time.

 

[goodnigh]

Ethanol gas corroded the needle and seat. You need to use an additive with every tank, or carbs suffer in short time.

What additive?

Also does not explain why the level held steady for 5 minutes

then gradually crept up to flood the engine.

mike

 

[c9zx]

For whatever reason the float isn't floating properly. Could be a mechanical stick in the pivot or could be a "leaky float". I agree it is an unusual symptom. Chuck

 

[goodnigh]

Holley instructs to adjust the float level 1/4 turn at a time and check results.

1/4 didn't quite do it so I added another quarter turn. Same thing, level is steady

for a few minutes then back to top, car stalls. This time a 1/2 turn, same thing.

After adding 1/4 turn for good measure, that's 1 1/4 turns now, I gave up.

Bought a new carb. The car is a daily driver and this would not be easy to fix.

I had problems with the float level about a year ago similar to this time but the

problem resolved on its own. Now it is back.

mike

 

[will e]

It might be that the seal between the needle and seat is just leaking a little.

 

[c9zx]

Holley instructs to adjust the float level 1/4 turn at a time and check results.

1/4 didn't quite do it so I added another quarter turn. Same thing, level is steady

for a few minutes then back to top, car stalls. This time a 1/2 turn, same thing.

After adding 1/4 turn for good measure, that's 1 1/4 turns now, I gave up.

Bought a new carb. The car is a daily driver and this would not be easy to fix.

I had problems with the float level about a year ago similar to this time but the

problem resolved on its own. Now it is back.

mike

Could the threads in the bowl be somewhat stripped allowing the Needle and seat to move?? Chuck

 

[goodnigh]

Found it.

We removed the float cover and the float. It was half full of gasoline.

We could not find a hole but if you shook the float in your hand it sort

of smelled like gas. My mechanic said this is an easy fix if we can find

the leak. We put the float in a bowl of hot water and looked for bubbles.

Sure 'nough, a pin hole leak in a solder joint, very small. Took 2 1/2

years to fill with enough gas to become inoperable. I may run this by

Holley as they have a warranty that may cover some of it.

mike

 

[mjlan]

Glad that you found the 'smoking gun'!

I think some Holley carbs come with solid plastic floats to combat this exact issue...

 

[goodnigh]

Glad that you found the 'smoking gun'!

I think some Holley carbs come with solid plastic floats to combat this exact issue...

Have not heard back from Holley.

We can fix the float, just a couple solder

patches. The micro one and then the hole

we drill to drain the gas. Already bought a

rebuild kit for the carb.

mike