Generator cranks but will not start; no error code displayed on the WEN controller.

Safety first: Turn OFF the generator and disconnect the battery negative cable. Allow the engine to cool before removing ignition components.

• Check spark plugs: Remove each spark plug and inspect the electrodes. Clean light deposits with a wire brush and check the gap with a feeler gauge, adjusting to WEN specifications. Replace the spark plugs if they are heavily fouled, cracked, or worn.
• Test for spark: Reconnect a plug to its wire, ground the plug body to the engine, and crank the engine briefly (battery reconnected). Look for a strong blue spark. No spark indicates an ignition problem.
• Inspect ignition coils and wires: Check the ignition coil(s) for cracks or burn marks. Ensure the plug wires are firmly seated at both ends and not damaged. Replace the ignition coil or spark plug wire set if defective.
• Check safety interlocks: Verify that low‑oil and E‑stop circuits are not disabling ignition. A grounded kill wire from the coil to the controller can prevent spark; inspect this wire for shorts.
• Retest start: After repairs, reinstall plugs, reconnect the battery, and attempt a manual start.