2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 31Get this manual
MAINTENANCE Maintenance-Free batteries are permanently sealed at the time of manufactureThe use of lead-calcium and AGM technology instead of lead-antimony allows the battery acid to be fully absorbedFor this reason, Maintenance-Free battery case is dark and the cell caps are not removable, since there is no need to check electrolyte levelNEVER attempt to add electrolyte or water to Maintenance-Free batteryDoing so will damage the case and shorten the life of the batteryRefer to the Battery Maintenance Video (PN 9917987) for proper instruction on servicing Maintenance-Free batteriesThe battery is located under the left rear fender
SPARK PLUG
1Remove spark plug high tension leadClean plug area so no dirt and debris can fall into engine when plug is removed2Remove spark plug3Inspect electrodes for wear and carbon buildupLook for sharp outer edge with no rounding or erosion of the electrodes4Clean with electrical contact cleaner or glass bead spark plug cleaner onlyCAUTION: wire brush or coated abrasive should not be used5Measure gap with wire gaugeRefer to specifications for proper spark plug type and gapAdjust gap if necessary by bending the side electrode carefully