KAWASAKI ULTRA 310X Stalling At Idle

Spark Plug Set (NGK PMR9B)

The supercharged 310X engine is highly sensitive to spark plug gap and heat range; carbon fouling occurs quickly during low-speed idling, creating a shunt path for electrical energy that prevents consistent combustion. This failure causes the engine to struggle against the rotational mass of the supercharger and pump at low RPMs, leading to a stall.

Fuel Pressure Regulator

The regulator maintains a constant pressure differential for the injectors; if the internal spring weakens or the intake screen clogs with ethanol deposits, fuel pressure drops at idle when pump voltage is lower. This results in poor fuel atomization and a lean condition that the ECU cannot compensate for via pulse-width modulation, causing the engine to die at closed throttle.

SKU: 49040-0718

Ignition Coil

Heat soak in the enclosed marine engine bay degrades the internal insulation of the stick coils; at idle, when the charging system output is at its minimum, the weakened coil may fail to provide sufficient voltage to jump the plug gap under the high compression environment of the supercharged engine.