1999-2004 Honda TRX400EX FourTrax Service Manual, Page 41Get this manual

MAINTENANCE Check the insulator for cracks or damage, and the electrodes for wear, fouling or discolorationReplace the plug if necessary (recommended spark plug: page 3-1)CENTER ELECTRODE

INSULATOR

Clean the spark plug electrodes with wire type brush or special plug cleanerCheck the gap between the center and side electrodes with wire-type feeler gaugeIf necessary, adjust the gap by bending the side electrode carefully
SPARK PLUG 0.6 0.7 mm (0.024- 0.028 in) CAUTION:

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