2000-2003 Honda TRX350 Rancher factory service manual, Page 56Get this manual
MAINTENANCE
SPARK PLUG
Disconnect the spark plug cap and clean around the spark plug base
PLUG CAP
Clean around the spark plug base with compressed air before removing the plug, and be sure that no debris is allowed to enter the combustion chamberRemove the spark plugSPARK PLUG
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
SIDE ELECTRODE
INSULATOR