2004 Bombardier Outlander 330/400 Factory Service Manual, Page 126Get 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
Intake portair filter contaminated (clogged) with dirt, sand, etc(leads to worn valves, piston rings and finally to leak of power)CAUTION: In case of piston rings andor valve replacement, always clean the whole engine and change oil and oil filter