Johnson - Evinrude 0582508 Ignition Coil

The Johnson - Evinrude 0582508 Ignition Coil is a widely used outboard engine component that fits a broad range of 2-stroke carbureted boat engines manufactured primarily between 1985 and 2006. This vital electrical assembly provides the spark voltage necessary for combustion across engine sizes ranging from small 4 HP portables up to massive V8 outboards.

Engine Compatibility

• Small Outboards: 4 HP Deluxe, 4.5 HP, 5 HP, 6 HP, 8 HP, 9.9 HP, and 15 HP models (predominantly 1985–1993 configurations).
• Mid-Range Engines: 20 HP, 25 HP, 30 HP, 40 HP, and 50 HP models (1985–2005 eras).
• Large Outboards: 3-cylinder through V8 configurations up to 300 HP (1985–2004 models).
• Crucial Exception: This ignition coil does NOT fit 150 HP or 175 HP "Loop Charged" models. Always verify your engine's specific model and serial number prefix before installation.

Testing and Troubleshooting Guide

If you are troubleshooting a "no-spark" or engine hesitation issue, you can test your existing coils using a digital multimeter set to the resistance (ohms) scale:

1. Primary Coil Test: Disconnect the primary wiring harness. Measure the resistance between the two small input spade terminals. A functional coil should register a low resistance, typically between 0.5 and 3.0 ohms.
2. Secondary Coil Test: Measure the resistance from one of the primary spade connectors to the deep interior of the high-voltage spark plug boot terminal. A proper secondary winding path should yield a much higher resistance threshold, generally reading between 3.0 and 10.0 kilo-ohms (kΩ) depending on the exact brand version.
3. Physical Inspection: Marine corrosion under the coil body can interrupt the ground path. Ensure the mounting surface bracket is thoroughly cleaned down to bare metal when mounting any new module.