2004 Skidoo ZX Series Service Manual, Page 66Get this manual
Section 03 TROUBLESHOOTING Subsection 01 (ENGINE)
The following chart is provided to help diagnose the probable source of troublesIt should be used as guidelineSome causes or corrections may not apply to specific modelNOTE: For the 1004 4-TEC engine troubleshooting, refer to 4-STROKE 1004 4-TEC ENGINEFor engine management system troubleshooting, refer to appropriate subsectionSYMPTOM ENGINE BACKFIRES
CONDITION
TESTINSPECTION
NORMAL USE1Check spark plugsaCarbon accumulation caused by defective spark plug(s)Clean carbon accumulation from piston and cylinder head and install dry properly gapped spark plug(s)2Check ignition timingaTiming is too advancedSet timing according to specifications (refer to TECHNICAL DATA)3Check for erratic sparksaPoor electrical connectionsRepairbFaulty statorReplace defective parts4Check carburetoraFuel passages obstructedClean carburetor and install new filter(s)bFuel level too lowAdjust float level according to specifications5Check cooling systemFan-Cooled Engines aLoose fan beltAdjust or replace fan belt (refer to AXIAL FAN COOLING SYSTEM)bDirty cooling fins or blocked air ductsCleanLiquid-Cooled Engines aLow antifreeze levelAdjust antifreeze levelProceed with leakage test (refer to LIQUID COOLING SYSTEM) and repair as requiredbDefective tank capReplace capcDefective thermostatReplace thermostatdAir in systemBleed system