If you have fuel coming out the top of the carburetor, or around the throttle shaft, it indicates you’re getting too much fuel in the carb.
This list is by no means exhaustive, but these are the most common causes of carburetor flooding.
#1 possible cause is the needle & seat:
Needle and seat
- inspect the carb surface for old gasket residue and clean carefully
- use the gasket included in the rebuild kit
- check for hairline cracks in the carb body where the seat threads in
- needle is pulling out of the seat too far and not reseating properly
- needle valve plunger spring collapsed (should 5mm on late carburetors, 8mm on pre 1971 carbs)
Is the float leaking? A brass float can be tested by immersing in hot water. Any bubbles coming from the float indicates a leak. A black Nitrophyl float can only be tested by weighing using a gram scale. Each of our float product listing have the weight stated. See the list of floats here
Purchase replacement needle and seats here
Float
- float level (settings can be found in the kit instructions or rebuild manual)
- leaking or saturated float
- brass floats can be submerged in hot water, if you see bubbles, you need a new float.
- worn float tabs
- hinge holes or float pin excessively worn or rough
Replacement floats are available in our catalog here
Fuel pump pressure is too high and overpowering the caburetor
Air horn gasket damaged or incorrect
Air horn screws loose
