Causes of Problem

Remedy

• Pre-ignition due to very hot spark plug used

• Pre-ignition due to ignition timing too much advanced

• High compression ratio in engine cylinder

• Excessive carbon deposits in combustion

• Cylinder head gasket projecting into the Combustion chamber

• Air-fuel mixture too lean

• Fit correct type of spark plug

• Adjust the ignition timing

• Correct

• Decarbonise

• Replace gasket

• Adjust Carburetor