Carburetor Troubleshooting


Flooding

• floats set too high

• float sticking, misaligned

• float needle seat worn or damaged

• BS34, float needle body o ring defect

• BS38, float needle body washer defect

• float ruptured


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Lean Air/Fuel Mixture


Lean - Idle

• pilot jet too small

• air leak

• pilot air screw not adjusted properly

• slide worn

• cheap pod filter blocking air jet


Lean - Acceleration

• float level too low

• jets clogged

• worn or damaged slide


Lean - Midrange

• air leak

• main or needle jet clogged


Lean - High Speed

• float level too low

• main jet too small

• main jet blocked


Lean - Full Range

• tank cap vent

• filters blocked

• air leaks

• worn slide


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Rich Air/Fuel Mixture


Rich - Idle

• pilot air screw incorrectly adjusted

• pilot jet too large

• dirty pilot circuits

• cheap pod filter blocking air jet


Rich - Midrange

• flooding

• main jet too big

• dirty air filter


Rich - High Speed

• flooding

• main jet too big

• dirty air filter


Rich - Full Range

• flooding

• dirty air filter


"Chirping" Carbs

• inlet manifold cracked, not sealing to carb

• inlet manifold gasket

• vacuum barb bung

• butterfly shaft seals

• diaphragm

• air filter manifold

• air mix screw o-ring