While putzing around on my 63 Falcon today I somehow hooked a piece of the carb linkage on my sleeve and yanked it right off the carb The problem is that there was a small spring that apparently popped out and went flying off to who knows where. Ok heer's pic to help explain. The rod and the clip that holds it on came off. The spring insdie the fitting went flying, can't find it. Looking the the rod I guessed that a spring from a ball point pent might fit the bill. Well it fits on the rod and in the fitting. But is it just right, too much spring, too little? The notch on the rod seems to be a locator according to the shop manual, but they weren't very specific about the position. I have not driven the car with this arrangement, but in the garage it seems to idle and rev up fine. Any help or advice would be appreciated. As close as I can tell the tag on the carb reads C30F B and A3AC
So a little more reading and it seems like this assembly is the bowl vent. Still unsure about that notch though, as in where it should be when the engine is cold or if that even makes a difference as long as the rod moves freely.
IIRC, there is supposed to be a ball also at the end of the spring. When your at wot or partial throttle it vents to the throat of the carb. At an idle it shuts off the vent, not sure why. Don’t take this to the bank! It’s been many years since I worked on one of these. If you get a problem driving down the road, it will be because your spring is to long/strong closing the vent to the fuel bowl. Simply cut some coils off till problem disappears. Bon s
Thanks! What would trouble look, act like? There is no check ball according to the shop manual and I found a video on YT that makes it look like this spring is pretty close to right. I'll take the car for a short drive to see how it goes.
If the fuel bowl is not vented, the atmosphere cannot push the fuel out of the bowel, through the jets and into the venturis. The car will act like it’s running out of gas, which is exactly what it would be doing.Alway remember there is no “suction” only differences of pressure. This will help understand a carburetor. Carburetors used to be vented to the atmosphere, but as emissions started to be a concern the manufacturers started venting to places that would burn the fumes. This is about the time this carb was made. It appears that this vent is for wot to allow more venting. You should have no problem. Bones
I have the basically the same carb on my 66 Bronco and from what I remember the spring is longer and lighter than a pen spring. I'd try it anyway's, got nothing to lose. Most of the spring tension would come from the spring from the accelerator pump anyway.
Thanks guys. OK so I let the car run until it was fully warmed up and thought the vent rod might move in, nope. Reved it up and no movement. So the vent rod is fully out closing the external venting to the atmosphere. Maybe too much spring? I guess I don't understand the functional difference between venting to the atmosphere vs venting internally.
Took the car out for a couple mile drive, no problems, ran as good as ever. But the vent rod is fully out closing the external venting to the atmosphere. So I guess I need to snip the spring a bit to let it vent to the atmosphere at closed or part throttle as designed. Gotta find more spring to test with. Thanks again for the help guys.
Actually there is little difference. The old engines vented everything to the atmosphere even the crankcase. The problem is cars smelled and the atmosphere was being polluted. Remember this, everything on that carb was put there for a reason. Parts , casting, machining all cost money, if it there , there must be a reason for it. Sometimes the reason has nothing to do with the actual running of the engine.... and sometimes it does. The rod works with the throttle position, problaly either opens or closes the vent with action of the throttle shaft. Been too long for me, can’t remember exactly how it works. Bones
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