Carb flooding
#1
Carb flooding
I have a 52 with a 215 motor, I believe the carb is a Holley 1904.
The carb is flooding, fuel is pouring out of the top of the bowl.
I have adjusted and re-adjusted the float several times. I checked the float, no leaks and it does float. I pulled everything apart and rebuilt it it. The float needle pin (not sure what its called) has a nice rubber tip with no blemishes and the seat is clean, I have noticed that it does seem to bind up a little, if I push the float up and let it drop, the pin stays seated.
Could my stock fuel pump be putting out too much pressure, is there a way to turn it down?
I am pulling my hair out trying to figure this one out.
The carb is flooding, fuel is pouring out of the top of the bowl.
I have adjusted and re-adjusted the float several times. I checked the float, no leaks and it does float. I pulled everything apart and rebuilt it it. The float needle pin (not sure what its called) has a nice rubber tip with no blemishes and the seat is clean, I have noticed that it does seem to bind up a little, if I push the float up and let it drop, the pin stays seated.
Could my stock fuel pump be putting out too much pressure, is there a way to turn it down?
I am pulling my hair out trying to figure this one out.
#2
Did you adjust the float drop? If the float can drop too low, it can't push the needle back into its seat, it would flood immediately. Drop is adjusted by bending the tang behind the seat. See (generic) picture. Thing is, I don't know what the spec is for your carb?
Fuel pressure will push the needle down, no problem with a little sticking.
Fuel pressure will push the needle down, no problem with a little sticking.
#3
Have the exact same problem on a '53, however my pump has a big time leak from the diaphragm to the atmosphere port on the side. Looked at my float, and after reading the post, think that it might solve my problem. Truck runs great for about 2 minutes, then floods out. If I drive it, it is usually ok, but just sitting is a 50-50 shot of flooding out or idling fine.
#4
Did you adjust the float drop? If the float can drop too low, it can't push the needle back into its seat, it would flood immediately. Drop is adjusted by bending the tang behind the seat. See (generic) picture. Thing is, I don't know what the spec is for your carb?
Fuel pressure will push the needle down, no problem with a little sticking.
Fuel pressure will push the needle down, no problem with a little sticking.
#6
Also the screw that attaches the float hanger, which is found after removing the inlet fitting, many time comes loose allowing fuel to bypass the gasket and filling the bowl no matter how/where you adjust the float. Hard to find large blade carb screwdrivers these days, you may have to fashion one from a piece of metal in order to tighten sufficiently. It's also a good idea to find something to 'prop up' the float hanger while tightening the screw as the hanger will try to follow the torque making it crooked in the bowl (you'll see what I mean.) Don't get crazy but it's imperative that the screw is tight (and that the gaskets are in place.)
#7
I heard this on another website, and it appears to be true. There are different sized orifices in the needle valves, depending whether the valve is used in a small carb or a larger one, but using the same body. So some rebuilders, and some rebuild kits, are supplying only the most common, which is usually the larger orifice types.
The downside to this is that a larger orifice takes more closing force than a smaller one to achieve tight shutoff, and some floats are simply not capable of putting enough force on the needle to close it. So it can be a case of too much fuel pressure, or too much pressure for the needle.
The 1904 as I recall has a pretty small float. If there is someone selling "genuine" OEM needles/seats for your carb (or one of the IH/Dodge/Jeep variants) it might solve your problem.
The forum I saw this on was for cars with the Rochester 2G carbs. The later 2G's had a needle with almost 50% more area and it turns out the rebuild kits almost always come with the larger needle, and they flood constantly. Happened to me.
The downside to this is that a larger orifice takes more closing force than a smaller one to achieve tight shutoff, and some floats are simply not capable of putting enough force on the needle to close it. So it can be a case of too much fuel pressure, or too much pressure for the needle.
The 1904 as I recall has a pretty small float. If there is someone selling "genuine" OEM needles/seats for your carb (or one of the IH/Dodge/Jeep variants) it might solve your problem.
The forum I saw this on was for cars with the Rochester 2G carbs. The later 2G's had a needle with almost 50% more area and it turns out the rebuild kits almost always come with the larger needle, and they flood constantly. Happened to me.
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