2002-2003 Bombardier Baja DS650 Service Manual, Page 59Get this manual
Section 03 ENGINE Subsection 03 (COOLING SYSTEM)
Supply combustion chamber with air pressureDIAGNOSE
Listen for air leaks: air escaping from spark plug means poor spark plug tightness or defective spark plug gasket air escaping from intake means leaking intake valve air escaping from exhaust means leaking exhaust valve airoil escaping from crankcase means damaged gasket andor loosened screws (refer to CRANKSHAFTBALANCER SHAFT) air bubbles out of radiator means leaking cylinder head gasket aircoolant escaping from cylinderhead means damaged gasket(s) andor loosened screws(refer to CYLINDER AND HEAD) air escaping into crankcase area means excessively worn cylinder andor broken piston ringsNOTE: For all the check mentioned above see the appropriate engine section to diagnose and repair the engine