IGNITION COIL 339-859738T1

Function and technical context

The ignition coil is the central component of the ignition system responsible for transforming the low voltage current coming from the magneto or control module into the high voltage necessary to generate the spark on the spark plugs. This part works directly within the ignition circuit of the petrol engine, determining the quality and exact timing of combustion in the combustion chamber. A failure in the ignition coil causes loss of power, difficulty starting, irregular engine operation and, in advanced cases, complete stoppage of the boat during navigation.

When to replace this part?

Typical symptoms of ignition coil degradation include misfire, progressive loss of revs, erratic throttle behavior, and difficulty maintaining a constant gear. Although there is no universal fixed time interval, it is recommended to check the condition of the coil at each seasonal maintenance, especially if the boat has been unused for several months or has been sailed in high humidity conditions. Preventively replacing the ignition coil prevents running out of propulsion at sea and prolongs the life of the engine by ensuring uniform and efficient combustion.

Mercury/MerCruiser

Equivalent manufacturer part numbers