5-2EC. Engine idlesirregularly or stalls.Trouble Possible Cause Remedy1. Spark plug(s) fouled or incorrecttype.2. Fuel system obstructed.3. Fuel contaminated or stale.4. Fuel filter clogged.5. Failed ignition parts.6. Warning system activated.7. Spark plug gap incorrect.8. Poor connections or damagedignition wiring.9. Specified engine oil not used.10. Thermostat faulty or clogged.11. Carburetor adjustments incorrect.12. Fuel pump damaged.13. Air vent screw on the fuel tankclosed.14. Motor angle too high.15. Carburetor clogged.16. Fuel joint connection incorrect.17. Throttle valve adjustment incorrect.18. Battery lead disconnected.1. Inspect spark plug(s). Clean orreplace with recommended type.2. Check for pinched or kinked fuelline or other obstructions in fuelsystem.3. Fill tank with clean, fresh fuel.4. Clean or replace filter.5. Have serviced by a Yamahadealer.6. Find and correct cause of warning.7. Inspect and adjust as specified.8. Check wires for wear or breaks.Tighten all loose connections.Replace worn or broken wires.9. Check and replace oil as specified.10. Have serviced by a Yamahadealer.11. Have serviced by a Yamahadealer.12. Have serviced by a Yamahadealer.13. Open the air vent screw.14. Return to normal operatingposition.15. Have serviced by a Yamahadealer.16. Connect correctly.17. Have serviced by a Yamahadealer.18. Connect securely.