2002-2003 Bombardier Baja DS650 Service Manual, Page 142Get this manual
Section 05 ELECTRICAL Subsection 05 (IGNITION SYSTEM)
DYNAMIC TEST An ignition coil tester available from after-market toolequipment suppliers can be usedCAUTION: Do NOT use coil tester on metal work benchFollow manufacturer instructionsIf the ignition coil is out of specification, replace itIf it tests good ensure the wiring and connectors are in good condition then continue the next tests
SPARK PLUG DISASSEMBLY
First unscrew the spark plug one turnClean the spark plug and cylinder head with pressurized air then completely unscrew
FOULING
Fouling of the spark plug is indicated by irregular running of the engine, decreased engine speed due to misfiring, reduced performance, and increased fuel consumptionThis is due to loss of compressionOther possible causes are: prolonged idling or low-speed riding, or running on too rich mixture due to abuse of choke, clogged air filter, faulty carburetor adjustment, incorrect fuel, defective ignition system, incorrect ignition timing, incorrect spark plug gap, lubricating oil entering the combustion chamber, or too cold spark plugThe plug face of fouled spark plug has either wet black deposit or black carbon foulingSuch coatings form conductive connection between the center electrode and ground