Tim Sullivan

Just installed two Zenith 3 barrel carbs on my car. They supposedly were rebuilt awhile back but I'm not so sure. I noticed that the car starts real hard and the accelerator pumps don't inject any fuel through the small tubes, viewable when you look down the carb throats and pump the linkage. I find it hard to believe that both carbs would be afflicted by the same problem --unless they are both gummed up? The side bar linkage works fine and I can see the accelerator pumps, on the side of the carbs, depressing the pumps when I move the linkage-- but no fuel injected through the small tubes.

Once finally started the motor runs fine and once in motion moves right along. I get a slight stumble when accelerating mid range (around 3k RPM) and of course if I floor it off idle, a major stumble. Points, plugs, plug wires, rotor and distributor cap are new. Timing is set and dwell reads right on spec.

Accelerator pump passages plugged up?

rw7810

I think you have hit upon the reason for the stumbles, if the accelerator pumps don't work, there is no transition. You need to investigate and get your pumps working.

Bob Williams
70 911T