2003 Bombardier Outlander 400 Factory Service Manual, Page 119Get this manual
Subsection 09
Section 03 ENGINE (CYLINDER AND HEAD)
GENERAL
NOTE: When diagnosing an engine problem, always perform cylinder leak testThis will help pin-point problemRefer to the instructions included with your leak tester and LEAK TEST section for proceduresAlways place the vehicle on level surfaceNOTE: For better understanding, the many illustrations are taken with engine out of vehicleTo perform the following instructions, it is not necessary to remove engine from vehicleAlways disconnect BLACK (-) cable from the battery, then RED (+) cable before working on the engine
SPARK PLUG
Removal
Unplug the spark plug wireClean spark plug area before disassemblyUnscrew spark plug