Hemi carburetor help

[erickson]

I have a couple of questions I’m hoping someone can help me with
My 1968 Hemi stock carbs
When it sits for a while both carbs are completely empty. Also it wants to flood sometimes. I took them apart and the floats look to be correct. Thoughts on what I should be looking for?

Thanks

 

[Richard Cranium]

Sadly, the fuel evaporation issue is normal.

You’ll need to provide more info when it happens on the flooding issue.

 

[steve340]

You could have a faulty needle valve.

 

[RJRENTON]

While fuel evaporation issues, due to the ethanol content, is the most prevalent, it MAY BE POSSIBLE to have a leak at one of the drilled passage closing plugs (visable from the under side of the carb, for both the primary and secondary main jet transfer passages). These closing plugs look like small aluminium mushroom shaped plugs pressed into the casting.....these almost never leak...but it is possible...GM QUADRA-JET carbs had a similar issue....the fuel bowl would empty after few days. Just my opinion of course.....
BOB RENTON

 

[erickson]

sometimes I have to drive it when I want to restart it in a few minutes it floods sometimes. Like gas is going into the engine. It also smells rich like it’s getting to much fuel at idle. I do have new cab kits for them.

Thanks

 

[AR67GTX]

This is a real long shot on the carb flooding but do your needles have the little spring wire connectors that hook on to the float arm, the apparent purpose being for the dropping float to dislodge the needle from the seat in case it’s sticky.

If those clips hold the float too tight it will smetimes prevent the needle from self-centering when the float is closing it, causing the carb bowl to fill with fuel and run out the vents. It happened to me 2 or 3 times before I figured it out. They need to be a loose fit.

Modern fuel, ethanol or not, is more volatile than fuel of 50 years ago and evaporates very quickly in these old vented bowl carbs.

 

[Pikser]

I found a leak in one of mine after Months of trying everything I could think of.
I finally took both carburetors and hooked them to a fuel line on an outdoor workbench. Using a small bottle hooked to the fuel line and filled them up. Found both needle valves leaking.

 

[erickson]

I will check things out tomorrow. Thanks for your ideas

 

[dvw]

Never seen an AVS or AFB leak fuel out of the bowl. The fuel evaporates plain and simple. Two fixes; electric pump ; or fill the bowls thru the vents with a squirt bottle of fuel. The flooding is a seperate issue. Either the needle isn't seating. The seat is loose in the carb. The float is misadjusted or heavy with fuel. The fuel pressure is to high.
Doug

 

[tanglewoodHemis]

I have a couple of questions I’m hoping someone can help me with
My 1968 Hemi stock carbs
When it sits for a while both carbs are completely empty. Also it wants to flood sometimes. I took them apart and the floats look to be correct. Thoughts on what I should be looking for?

Thanks

I have two 66 426 Hemis that do just what you describe. Both are fully stock. Since I have owned them I have used non-ethanol gas in them. (One 4 yrs, the other 2 yrs)
Both fire up instantly within a an hour or two of being shut off. After about 5 hrs of sitting on a summer day it acts like it is flooded. Sitting overnight it starts instantly the next day.
Let sit a week and it will need about 30 secs of cranking, then give the starter a few min break, then hit the starter again and it starts immediately.
It appears to me that after sitting for days that fuel line drains back into the tank.

 

[AR67GTX]

i don’t think the bowl is syphoning back - the fuel needle and seat, and bowl fuel level create a syphoning break. If the fuel were not evaporating it would start on the bowl and fuel would recharge the bowl before it died normally even if the line had drained back to the pump. Even with todays non-ethanol gas, the formulation is far different from the 60s and evaporates much quicker due to its low temp vaporization threshold and overall volatility. I know if I spill some gas on my driveway on a warm day it’s gone in a very short time. It’s gone much faster than what my foggy memory recalls from the 60s and early 70s.

edit: Had to rewrite due to earlier edit mistake.

 

[erickson]

haven’t had much time to work on it. I found out I have electrical issues. When the car won’t start I pushed on the bulkhead connection it starts
Will be cleaning it today and bypassing the voltage gauge. Then back to the carburetors Thanks for all the help