My rust sacrifice (66 f-100 w/300 six) has a Carter YF/Motorcraft carby on it that has developed a problem I am having trouble tracking down. It started dribbling gas out of the acceleration jet tube at all times, which makes the engine run really (plug fouling) rich at idle and greatly worsens fuel economy at higher speeds. I installed a carb kit 3 years ago when I started driving this and have ALWAYS ran a fuel filter. The float level is just a little low and the needle and seat hold perfectly. I am running a fuel pressure regulator, which is running in the almost shut off position (I don't know how many PSI, don't have a guage on it).
I thought perhaps something was in the accelerator pump outlet check valve, so I replaced the ball and weight in the carb with the little needle they send in a carb kit, which did not help. I can reach my finger down an plug the accelerator tube off with my finger and everything return so normal. The accelerator pump works because it shoots a good stream of fuel when you accelerate the motor.
Since this is my work ride, I took the Carter YF off my 216 that died last summer and installed in on the F**D, and now it runs fine. If someone has an idea on the F**D oem Carter YF, I would like to hear it. It just started messing up all at once--no backfires or anything like that. I gotta get the right carby on before winter because it would take a lot of work to get the Chevy choke set up to work on the F**d engine.
Any suggestions would be greatly appreciated!
