|Problems||Carburetor doesn't adjust properly||Carburetor floods||Fuel leaks at shaft||Internal fuel leak||Misses or surges||Stumbles or loads up||Engine won't idle||Rough idle||Backfires||Bogs||Hard starting||Lack of power||Pinging at moderate cruise just off idle||Engine stalls on hard braking||Low fuel economy|
|Fuel pressure too high. Fuel regulator may be needed. See #3 below||X||X||X||X|
|Check for dirt or metal in needles and seats. Needles and seats may need replacement. See #1 below||X||X||X|
|Check for air leaks. Make sure carburetor and manifold gaskets seal properly. All outlets must be plugged or connected.||X||X||X||X||X||X||X||X||X|
|Check ignition system. Replace parts as necessary. Adjust timing to proper specifications.||X||X||X||X||X||X||X||X|
|Check choke adjustment.||X||X||X||X||X||X||X|
|Change carburetor fuel filter and/or in-line fuel filter.||X||X||X||X||X|
|Check float level and drop.||X||X||X||X||X|
|Check idle mixture screw adjustment Click Here.||X||X||X||X|
|Increase accelerator pump stroke. Pump squirter size change may be needed.||X||X|
|Off-road vehicle may need spring-loaded needle and seat kit.||X||X|
|Check for dirt blocking the low speed circuit. Clean unit and apply air pressure. Install in-line fuel filter.||X||X||X||X|
|Check floats for leakage. Replace if necessary.||X||X||X||X|
|Check air horn gasket. Replace if deterioration or breakage is present.||X||X||X||X|
|Fuel is boiling due to excessive under hood temperature. See #2 below.||X||X||X||X|
|Fuel pressure too low. Check fuel system.||X||X|
|Check secondary latching device and rod for proper movement.||X|
|Lower float level Slightly .||X|
#1 Dirt/metal shavings between the needle and seat or a "sticking float": To correct either of these problems, lightly tap the carburetor fuel inlet area with the handle of a screwdriver. If flooding continues, pinch the fuel line (if possible). Start the engine and let it run until it stops. Release line and restart engine. If flooding persists examine the needles, seats, float level, and float drop. Adjust or replace parts if necessary.
#2 Excessive under hood temperature: Ensure fuel line is not located too close to heat sources such as the exhaust or block, causing expanding fuel to be forced past the needle and seat. Fuel can also boil inside the carburetor due to missing gaskets, spacers, or heat shields. Also check to see if the exhaust heat riser is stuck, allowing excessive heat under the carburetor.
#3 Excessive fuel pump pressure: Avoid extremes in fuel pressure. At IDLE, there should not be any more than 5.0 psi; if the vehicle has an adjustable fuel-pressure regulator, set it to 4.5 psi. With most fuel pumps the minimum fuel pressure is encountered at high rpm and WOT. Fuel pressure should not drop below 2.0 psi. If it does, a fuel pump with more capacity may be required.