Edelbrock Carburetor
Trouble Shooting Chart

Possible Solution 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
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

Too lean. See Tuning Procedure.



X



X
X X

Check float level and drop. 
X X

X






X X
Check idle mixture screw adjustment.  X




X X





X
Too rich. See Tuning Procedure.




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 or metal in needles and seats. Needles and seats may need replacement. See below.
X
X









X
Check for dirt blocking the low speed circuit. Clean unit and apply air pressure. Install in-line fuel filter #8873. 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 below.

X






X


X
Fuel pressure too high. Fuel regulator may be needed. 
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 from 11/32" to 7/16". 












X

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.

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. Use Edelbrock Divided Heat Insulator Gasket #9266 for dual-plane manifolds, Square-Bore Heat Insulator Gasket #9265 for single-plane manifolds, and #9267 Heat Insulator Gaskets for dual-quad manifolds.

Excessive fuel pump pressure:  

 

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