CHAMPION QL77JC4 SPARK PLUG

Function and technical context

The Champion QL77JC4 spark plug is the element responsible for generating the electrical spark that initiates combustion in the cylinder of the petrol outboard or inboard engine. It is part of the ignition system and works closely with the ignition coil, the distributor and the engine control unit. A bad spark plug causes incomplete combustion which results in loss of power, excessive fuel consumption, starting difficulties and irregular exhaust emissions. The Champion QL77JC4 is designed to maintain the electrode at the optimal working temperature, preventing both carbon fouling and harmful preheating of the electrode.

When to replace this part?

The most common symptoms of a worn or damaged spark plug are: difficult or failed starting when cold, jerks and loss of speed at low revolutions, irregular engine running ("miss" or misfire in one or more cylinders) and a notable increase in petrol consumption. As a general maintenance rule, it is recommended to inspect the spark plugs at each seasonal inspection and replace them every 100 hours of navigation or annually, whichever comes first, since the electrode is eroded by the continuous electric arc. Replacing spark plugs preventively before a long voyage is one of the most economical maintenance measures to avoid breakdowns at sea.

Compatibility