All,
I have been reading through the posts here to try to find help with my problem, but I havent found anything yet.

I have a 1973 Autolite 4300. I rebuilt it using a GP Sorensen kit. I replaced both needles, both seats, all gaskets, rubber pieces, etc. Now, my truck starts up and runs fine, but I get gas spewing out of the top of my carb (I think its coming from the bowl vent tubes maybe) I posted before and everybody says adjust the float level. So I got the level for the big needle/seat(primary???) set to 49/64 and I got the level for the small needle/seat(secondary???) set to 1/16 (Well its probably about 1/4 actually. That thing is hard to adjust lol)

But I still got gas spewing out the top of the carb. I talked to a tech at Pony carbs and he suggested I plug the small needle/seat and just run off the large one. I tried that but when I did it, there was no gas getting to the carb. I tried setting the other float to 56/64 but there still was NO gas getting to the engine. At this point I still had the old needle/set in there.

SO I went ahead and put the new needle/seat (both sides) in the carb, set the floats to 49/64 and 1/16 (1/4 probably though), and then when I fired it up this time once again I got fuel spewing out the top. Now the truck runs, and it sounds like if all this gas wasnt spewing out the top and getting sucked back in it probably would run good.

So can you give me any advice? I got pics of me replacing the needles too if thatll help. Thanks in advance!

paulbunyan

 

I am curious if you may just have too much fuel pressure. Have you checked it? It should be no more than 6 to 6.5 psi.
I am assuming that you float is good?

 

No I was thinking about checking that too. Ill do that next

 

Ok I resolved my own problem.

I read somewhere on the internet that on Autolite/Motorcraft 4300s you can plug the auxilary needle/seat, and just run off the primary one. That cures the problem I am speaking of. It seems like Ford had a big problem with these things catching on fire from gas spewing outta the vent tubes. I have been corresponding with an old Lincoln mechanic. Hes the one who got me straight.

I tried plugging the aux seat before but I still had the old needle/seat on the primary side, so when I plugged the aux side before, no gas was coming through on the primary. So this time when I plugged the aux side, I replaced the primary seat as well with a new one and I changed the float level on the primary side to 45/64. Once I did that the run started and ran with NO gas spewing outta the top of the carb.

Now I just have to adjust the idle circuit because when I let off the gas pedal my car dies. I am thinking I just have to back out the idle mixture screws a bit. Am I correct, is that the proper way to adjust the idle, by using the idle mixture screws?