I drained the small tank in the front of the carb and started it up (thought maybe it just started with too much gas in there???). She ran ONLY long enough (approximately 10 seconds) before the overflow began again at the same rate it did in the past.
The gas is still coming out ferociously from those two holes in the front (as noted in the picture in the link above).
it should be near the fuel inlet of the carb linked to the float. if the bowl is empty and the float is not touching the bottom of the bowl its probably stuck open
1969 Ford F250 Custom Cab 360/C6 - currently under de-construction
My 72 360 2bbl has the same problem!!!! See my post. "360 won't start."
This seems to be common. I sure wish I knew what was going on here.
I have done alot of parts changing. Now for the slow methodical trobleshooting with the help of some very good folks on this website. THANX FORDIFICATION!
You got the easy part done, talkin' about it.
'72 F100 Sport Custom 2wd
360, C-6, PS, PB, Front disc conversion
Ok remove the top of the carb, remove the float the needle half of the " needle and seat" should come out with the float. Inspected the needle soft tip for damage or debris, should be clean and smooth. look in side the seat for debris and should also be smooth. Make sure the seat is tight in float bowl, use a large blade screw driver. the float bowl should only have gas in it no sand or other crap in the bottom. There is a possibility that that carb casting could be cracked where the seat screws in or be pores enough to allow fuel in unmetered. Now reinstall the float with needle attached, gently push down on needle till it seats. The float should have cast line near the tip. At this line is where the float level measurement is taken. Use a straight edge across the top of the bowl, w/o the gasket, and small steel ruler 32nds graduations. Now the float level is different for many different applications, and I don't remember what it is, (last did this in 1991). I will say that you should be able to idle drive normally with a float level between 5/16 and 7/16. If someone has the float level spec handy please post it, and correct me if my memory has failed again
actauly i beleive that is the specs from the rebuild instructions.
"It is better to keep your mouth shut and appear stupid than to open it and remove all doubt." - Mark Twain
'70 f250 4x4 Crew cab 460/C6 '72 F100 390/C6 9.8 MPG AVG. '89 Mercury Cougar LS Dual Exh. V6 . 18.9 MPG AVG. In Town.
I don't want to give em a heart-attack. That is what would happen if I answered the door in the buff. Heck it almost scares me to death when I step out of the shower and look in the mirror.~Mancar1~
fuelly.com
Calling Keith and/or Robert (DuckRyder)! On Ford_dude72's post you offered up 3 reasons for flooding out the holes in the top of the carb.
One of which "B) the fuel pump is producing so high of pressure it is forcing the needle valves off their seats." is definitely MY problem.
I started my truck w/o the top of the carb hooked up so I could see how/why that tank was filling & overflowing. What I noticed immediately was the HIGH pressure (definitely >6lbs) that the fuel came in at! It was like a pressure washer!
How do I regulate [slow] the flow at which gas is pumped into the carb? I have a new (refurbed) mechanical pump that I bought from LMC.
Bonnie_72_F100 wrote:Calling Keith and/or Robert (DuckRyder)! On Ford_dude72's post you offered up 3 reasons for flooding out the holes in the top of the carb.
One of which "B) the fuel pump is producing so high of pressure it is forcing the needle valves off their seats." is definitely MY problem.
I started my truck w/o the top of the carb hooked up so I could see how/why that tank was filling & overflowing. What I noticed immediately was the HIGH pressure (definitely >6lbs) that the fuel came in at! It was like a pressure washer!
How do I regulate [slow] the flow at which gas is pumped into the carb? I have a new (refurbed) mechanical pump that I bought from LMC.
Thanks!
That sounds like the fuel inlet needle stuck open. If you want to be sure get a fuel pressure gauge and check but I had that same thing happen to me before and it was the inlet needle
1969 Ford F250 Custom Cab 360/C6 - currently under de-construction
It is hard to tell pressure by sight, most mechanical pumps produce 90-110 gallons per hour, which is a good bit through a small fuel line. So you could have good volume without high pressure.
Definitely follow Keiths very excellent instructions re: examining the float level and needle.
If that all checks out O.K. then you should verify the pressure with a gauge. If it is in fact high you can insert a pressure regulator between the carb and pump.
FYI I have a 110 GPH Carter pump on mine with no regulator on no problems with a Holley.
mine would do that with with the stock rmaned ford pump, when i adjust the float to close when the float hit 5-7/16" that went away and only happened again hen the fuel in the bowl dipped down low enough to cuase the float to fully open the needle.
"It is better to keep your mouth shut and appear stupid than to open it and remove all doubt." - Mark Twain
'70 f250 4x4 Crew cab 460/C6 '72 F100 390/C6 9.8 MPG AVG. '89 Mercury Cougar LS Dual Exh. V6 . 18.9 MPG AVG. In Town.
I don't want to give em a heart-attack. That is what would happen if I answered the door in the buff. Heck it almost scares me to death when I step out of the shower and look in the mirror.~Mancar1~
fuelly.com
Solved. I took out the float/needle and examined for cleanliness (they were clean). I also suctioned out the bowl (found a LITTLE bit of gunk in there). I did measure and bent the float assbly just a tiny hair to meet spec.
I let her idle for about 2 minutes straight and she didn't overflow. Gave her gas and she revved up w/o overflowing.
I still have the problem that when I give her gas she shuts off (floods? maybe?).
I spoke TOO soon. The overflow came back when I was working on her tonight. She runs for about 30 seconds, long enough for the tank to fill then starts overflowing. Likewise, if I give her gas, she'll overflow stronger & sooner. The gas comes out the two holes on top of the tank.
Can these holes simply & safely be plugged?
- 360 FE with a 2bbl carb
- clean needle/seat
- float @ spec
- clean carb tank
- new gas tank
- new mech fuel pump
- new gas lines
- new gas
would be greatly appreciated.
Now for the slow methodical trobleshooting with the help of some very good folks on this website. 
THANX FORDIFICATION!
