MTFCA Forum

When complete and fully installed, what would cause gas to leak from the hole at the bottom of the stem?

for starters, that float is the wrong one...buoyancy and leverage are all wrong

the cause of the "leak" is the fact that due to insufficient lift the float valve has failed to fully seat and you are not leaking, you are overflowing

Scott. Thanks for your input. I failed to mention that the float that I installed is new from Lang's. The picture shown is when I disassembled the G prior to rebuilding. I think I have the float lever setting incorrectly. I set it at 5/16" body flange to float top. Perhaps increasing to 3/8" might prevent the problem? Do you think 3/8" is good or a larger distance?

it isn't so much where the float lays, as it depends on how deep the puddle of fuel is over the jet and the pickup tube for idle must be immersed.

too deep and it will flow out the overflow

if you have a metal tipped needle and it's old, then it's likely worn out
if you have a metal tipped needle and it's new, it may not have a good enough finish to seal properly...even a properly made needle will leak prior to being given a bit of a TAP to drive the needle into the seat to impress it.

if you have a viton tipped needle and it is leaking then the float is maladjusted

all of the fuel level settings must be done by viewing DOWN through the carb with the top off to actually visually inspect/measure the puddle depth

it's annoying

Scott. The needle and seat that came with the G looked good without any scaring or scoring. I have a Viton tipped needle and will install it. If all else fails I'll buy a new needle and seat set in addition to adjusting the float lever. Thanks again for the valuable information.

The best way to set up a "G" is to get the MTFCA carburetor book. It's worth it to make the setup jig so you can see the "puddle". Measurements are a good suggestion for a starting place for float height.

FWIW, the newfangled composite float is a bit bulky compared to the original cork. Fortunately it is easy to shape. I approximated the cork profile and compared the weight to the cork float.

I have always had very good results with the Holley G carburetor.

You're welcome

once the viton tipped needle/seat are installed be certain to NOT tap it, or press it closed...only the weight of the float (MAX!) should be allowed to bear down on it...that tip can become damaged if abused...otherwise they are very long lasting.

Finally, with all gravity fed systems, you MUST have a fuel shut off and you must use it. You can go a long time without a leak and then one night, you could empty your tank due to a fleck of crud getting into that needle. All gravity fed systems will eventually leak.

A bit fuzzy but readable: Holley G how-to from a 1920 service bulletin.