53 Cub fuel issue

[patdaddy]

Howdy. I’m having an issue with my Cub. It’s almost
like the fuel system is too airtight. I can turn the fuel on at the sediment bowl, and it won’t even fill up and flow out the line. If i disconnect the line, it’ll fill up and pour out. Put the line back on and it quits flowing. I have one of those new free tall fuel caps, could it not be venting? I have an about 2” piece of hard line at the bowl, then rubber line to a fuel filter, then rubber line to the shut off, then rubber line to a 2” piece of hard line at the carb. Any ideas? Thanks

[k hutchins]

A couple things come to mind.
1 is your filter oriented correctly for flow? I've installed them backward myself before by accident.
2 what is your float setting? I just had an issue where when the carb was assembled the float was hitting the bottom of the bowl, then pushing up enough to close the needle.

Pull the plug on the bottom of the carb to make sure you have good fuel flow.

[Eugene]

And you need a gravity flow fuel filter, not a fuel filter for a car or tractor with a fuel pump.

[patdaddy]

Thanks for those suggestions. The problem is, the fuel doesnt even want to get to the filter. It doesnt want to leave the sediment bowl. No line connected, fuel flows fine. Line connected, fuel doesnt want want to flow. Like its airtight, not venting. Its the wierdest thing.

[Eugene]

Replace the fuel line.

[k hutchins]

Check your float. If the needle valve is closed it can't flow if there's no where for it to go.

[Bob McCarty]

If the rubber line has been on a while, ethanol in the gas may have caused the ID to decrease with the deterioration it can cause.

[patdaddy]

I actually use ethanol free gas, so i dont believe thats the issue. I think i may replace the sediment bowl assembly and line with a new hard line.

[Barnyard]

You have a vapor lock. Unscrew the sediment bowl to let some air in. You should see some fuel movement.

[Don McCombs]

Does the tractor start and run?

[Glen]

Hi,
Cubs originally came with a metal gas line, from the gas strainer to the carburetor.
It won't deteriorate like a rubber gas line could.

Below is a listing at TM Tractor for a new metal gas line.
This gas line is for Cubs with a vertical exhaust system.
The threads have to be good, and the original size, in your gas strainer, and carb, to use it.

http://www.tmtractor.com/new/fl/864fp.htm

There is supposed to be a screen above the gasket in the gas strainer.

[patdaddy]

If i pull the bowl off, put it back on, but have the fuel line connected, the fuel wont even begin to enter the line. The bowl wont fill high enough to enter the line. If i remove the line, the bowl will fill and flow out the line hole. Put the line back on, no flow. It seems like attaching the line prevents any air from allowing fuel to move.

[Eugene]

Remove the fuel line at the carburetor. See if you have fuel flow.

[inairam]

I am not a fan of the inline fuel filter. The bowl nd the filter on the top of the bowl is all you need. Like Barnyard said you can vabor lock the bowl.

[tomstractor]

If you open the drain on the bottom of the carb you will see the bowl fill, the air is just locked in the bowl with no where to go. When the carb
needs fuel it lets the air out with the fuel and fills the bowl with fuel.