2003 Bombardier Rally 200 Service Manual, Page 70Get this manual
Section 03 ENGINE Subsection 02 (TROUBLESHOOTING)
ENGINE GENERAL
SYMPTOM CONDITION TestInspection ENGINE BACKFIRESNORMAL USE1Check spark plug andor electrical systemaCarbon accumulation caused by defective spark plugClean carbon accumulation and replace spark plugbElectrical system has failureReplace defective part(s)2Check leakage on intake manifoldaAir leak on intake systemRetighten screws andor replace intake manifold3Check exhaust air leakingaExhaust gasket is leakingRetighten screws andor replace exhaust gasket4Check intake valve(s) for leakingaIntake valve(s) is (are) leakingRepair or replace valve(s)5Check if fuel supply is to less at high RPMaFuel line is contaminated andor bent (engine gets lean)Clean andor replace defective part(s)