2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 319Get this manual

IGNITION SYSTEM Spark plug gap: 0.60.7 mm (0.020.03 in) CORRECT For CDN 4.Ignition spark gap

INCORRECT

Repair or replace the spark plug

Disconnect the spark plug cap from the spark plugConnect the dynamic spark tester as shownTurn the main switch to "ON"Check the ignition spark gapCrank the engine by pushing the starter switch, and increase the spark gap until misfiring occursMinimum spark gap: 6.0 mm (0.24 in) OUT OF SPECIFICATION OR NO SPARK

2 Spark plug cap Spark plug
MEETS SPECIFICATION

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives