- Carter B&B Doesn't Start After Sitting
- Adjusting the Idle Mixture Screw Has No Affect
- Engine Only Runs With Choke On
- Gas Leaking Out of Throttle Shaft
- Why is my B&B Flooding?
Carter B&B, BBR Carburetor Problems & Solutions
Below you will find questions that users have asked about the Carter 1 barrel carburetor. The questions are followed by our best guess answer. We say best guess, because we don't have the carburetor in front of us and users often leave out important information.
Below you will find questions that users have asked about the Carter 1 barrel carburetor. The questions are followed by our best guess answer. We say best guess, because we don't have the carburetor in front of us and users often leave out important information.
Throttle Valve Is 1/2 Open
That is correct: without an external throttle return spring the throttle plate stands 1/2 of the way open. This was done on many Carter carbs (and some Strombergs) so that the accelerator pump was constantly "pre-loaded" no matter how much wear might be in the linkage.
I experienced the downside of that engineering for myself in 1977 when the throttle return spring broke on my '67 Plymouth and the engine immediately accelerated to half-throttle. Luckily, I new exactly what to do (thanks to good prior instruction) and an accident was avoided: pop it into neutral, shut off the engine and coast to the side of the road.
Hesitation or Bog
Your engine hesitation when stepping on the gas can be caused by a couple of things.
Fuel Bowl Empties Overnight
One would be the distributor advance not working properly.
The other might be the accelerator pump circuit.
- The Carter B&B uses a leather cup on the accelerator pump. Be sure it didn’t dry out and curl up.
- With the engine off look down the carburetor bore. Pump the gas. You should see a good stream of gas come out of the main discharge.
- No squirt? Something is plugged.
- The main discharge can get plugged up because they seldom get cleaned. Look for the aluminum plug on the side of the carburetor just below where the top and main body meet. With the top off look down at the main discharge. Remove the plug and take the main discharge jet out. The jet comes out with a screw driver and they break easily, so if it doesn’t come out easily, then leave it in and clean it thoroughly. From there clean and blow out all of the passages.
- Some of the B&B have an intake check ball on the bottom of the fuel bowl. Take the plug out and make sure the check ball is clean and loose. Also can you blow air through to the pump well? This is how the fuel gets into the pump well.
Fuel leaking around the main discharge jet.
- Look for loose jet
- Crack in the jet, or in the carburetor body surrounding the jet.
Fuel Bowl Empties Overnight
Some possibilities:
- Fuel is percolating - Engine gets hot, then you shut it off. Gas boils over into the engine. A good indication would be fuel coming out the throttle shaft when turning off the engine. See Percolation.
- Fuel evaporates - Today's fuel evaporates and a much greater rate than it did pre non lead. Try other grades of fuel. If possible, use non ethanol gas. When starting this type of problem, don't pump the gas pedal. If the fuel bowl is empty then pumping the throttle prolongs the problem. Crank a few seconds to let the bowl fill, then pump once.
- After turning the engine off look down the carburetor to see if gas is still running into the engine. If it is, and it shouldn't be, then the check ball in main discharge may be leaking. Gas cap is non vented and should be vented type, bowl vent should not be closed off.
- Gas leaking out the bottom of the fuel bowl. This isn't hard to figure out. Place paper under the carburetor full of fuel overnight.
