2002 Bombardier Quest 650XT Service Manual, Page 100Get this manual
Subsection 08
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 following illustrations are taken with engine out of vehicleTo perform the following instructions, it is not necessary to remove engine from vehicleAlways disconnect the negative wire from the battery before working the engineEven if the removal of many parts is not necessary to reach another part, it is recommended to remove these parts in order to check themFor installation, use the torque values and Loctite products from exploded viewsClean threads before using Loctite product when installing screwsWhen disasembling parts that are duplicated in the engine, (eg: valves), it is strongly recommended to note their position (PTO, MAG side) and to keep them as "group"If you find defective component, it would be much easier to find the cause of the failure among its group of parts (eg: you found worn valve guideA bent spring could be the cause and it will be easy to know which one among the springs is the cause to replace it if you grouped them at disassembly)Besides, since used parts have matched together during the engine operation, they will keep their matched fit when you reassemble them together within their "group"