I'm not a Holley guy; no book in the library about them. I have a 4160 series carb on my ford 460 that is pumping fuel out the air vent tube on the back of the carb when it's running. I assume the issue is too much fuel in the bowl but how do I adjust it? Do I turn the screw on to of the bowl out and then lock it down with the jamb nut? and if so have much do I start with in terms of the number of turns? When I rebuilt the carb I tried to put everything back at the same place as when I took it carb apart because it ran so well before. It didn't work with the distributor but that is a different issue. Thanks for the help. I'll be buying a book today.
Adjust the floats by turning the screw counterclockwise (this raises the float) until fuel barely dribbles out of the side bowl screws. Then lock the nut. If it doesn't fix the problem check the gaskets used are for the carb. 4165/75 metering block gaskets are different and will cause the carb to do as you described. If this did happen odds are you fouled a few plugs too. Ray
It may only be a float adjustment as has been said, but if the needle and seat are old, float is fuel-soaked, or if there's debris keeping the needle from sealing on the seat, you get the same symptom. If adjustment doesn't do it, it'll have to come apart. The fact that it was OK before the rebuild tells me it's likely an adjustment is all that will be required. Devon
So I bought the book and read the part that I think are relevant. I turned the needle and seat out ( I think) with no change. I didn't pull the sight plugs out to see if the float bowl are too full yet. I'll try that tonight.
OK, got the truck running on Wed night. It's not very happy but it moves under it's own power without any leaks of a liquid. Vacuum is a differnt story. I still don't rally understand how to properly adjust the float level by turning the needle and seat in or out and using the nut to lock it in place. It seems to me that there aren't enough threads on the needle to allow for proper travel and still lock the setting. If the mericle of combustion takes place again on Monday I am planning on trying to resolve the vacuum routing and leak issues. I'm glad I don't have to try and pass the emmissions test with this thing. BTW, a 460 that is running 9.5:1 sounds good even with a few issues to be worked out. Much better than 8.0:1 or so before. I just got the notice for the Jeep and it has developed a roughness the was not corrected by as tune up. I'm thinking a vacuum leak and or a combination of vacuum leak and valvetrain issue. I've had a flat lobe on the cam before with a 360 in one of my other Wagoneersuzzled: . And did I mention that my daily driver is parked in the garage because it needs a cam sensor or something of the sort.:rant: At least the Buick has a q-jet and is put away for the winter. It will get a carb retune over the winter with a step up in jet, needle and rod sizes to give it all the power it should have.
So I go the 4160 running a lot better today. I read a little and fiddled a lot. Fixing all the vacuum leaks and getting the routing of the vacuum lines correct made a huge difference. Then I started adjusting the float bowl levels; I don't really get how the screw and nut adjust it when the nut is on the needle correctly, i.e. the indexing slot and the top of the needle are mated up. Anyway, about two full turns of the screw and the nut on the back bowl did wonders. Then a bit of adjustment on the mixture screws and the idle screw. Now it actually runs smooth and doesn't spit fuel out the vent tube. I did remove the sight screws enough to have fuel running out. Any siggestions about more adjustments?
I would find out what initial timing the engine likes meaning it fires up right away when hot or cold then adj. the pri. float when the car is idling hot. Then set the idle mixture screws for best vacuum in gear (I add a 1/16 of a turn out). When the initial is adjusted you may have to work with the dist. mech. advance to have it come in sooner or later as the engine likes and possibly limit the max. centrifugal advance. Adj. vacuum advance canisters are avail. if you really want to dial it in for street driving. Timing is everything. Ray
The Holley website has great how to videos. or YouTube. screw/jam nut-NO the screw locks the nut, the nut raises and lower the float level. Break the screw loose, set the level with the nut, tighten screw.:Comp:
