Hi, Anonymous if your carburetor or exhaust is:
COUGHING is usually caused by an air leak in the intake system and will generally have the same telltale signs, a wet or damp build up of oil/gas seepage at the intake manifold to cylinder head or carburetor to intake manifold connection and in rare instances a worn throttle plate shaft and or seals.
POPPING on deceleration is usually caused by a lean fuel condition or an air leak in the exhaust system and is generally located where black carbon soot is seen as a flashing build up from any joint connection. This condition can easily be remedied by removing and cleaning both joint pieces and reassembling with high temp silicone and torquing the exhaust clamp to the proper spec.
SPITTING is usually caused by a faulty accelerator pump and or nozzle, or the float bowl needle and seat leaking and overflowing through the main jet mixing well nozzle, or the air-fuel mixture screw is adjusted too lean.
BACKFIRING is usually caused by a sticky/tight intake valve or a timing issue, 180 degrees out or cam chain off 1or 2 teeth.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
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Kawasaki ZXR400 Service Manual Supplement
OEM Parts for Kawasaki
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