Ski-Doo Ski Doo GSX 2005 [915/1429] Engine is misfiring erratic spark at spark plug normal use

Section 02 TROUBLESHOOTING GUIDE

Subsection 05 (ELECTRICAL SYSTEM)

Symptom: ENGINE IS MISFIRING — ERRATIC SPARK AT SPARK PLUG (NORMAL USE).

1. Verify misfiring by observing flash of stroboscopic timing light; unplug connectors between

magneto/generator and vehicle wiring harness to isolate problem. Check condition of con-

nectors.

- Defective spark plug(s) and/or cable(s)/cap(s). Defective electrical system wiring harness and/or

accessories and/ignition cut-out switches. Condition of connector terminals. Replace defective

parts and/or repair damaged wires. Replace defective switch(es). Clean terminals and apply

silicone dielectric grease.

Symptom: ENGINE IS MISFIRING — ERRATIC SPARK AT SPARK PLUG. (RIDING IN DEEP

AND THICK SNOW.)

1. Perform all verifications outlined under ENGINE DOES NOT START — NO SPARK AT SPARK

PLUG.

2. Verify spark plugs. Proceed with spark plug analysis in order to identify source of problem.

- Defective and/or worn spark plug(s) and/or cable(s) and/or cap(s). Replace defective part(s). Pro-

ceed with ignition system testing procedures. Perform engine analysis.

Symptom: FOULED (BLACK) SPARK PLUG TIP.

1. Check carburetor(s).

- Carburetion is too rich. Adjust according to specifications (refer to TECHNICAL DATA).

2. Check injection oil consumption.

- Injection pump flow is too high. Adjust according to specifications or replace.

3. Check oil quality.

- Poor quality oil. Use Bombardier injection oil.

4. Check engine compression.

- Leaking piston ring(s). Replace.

Symptom: SPARK PLUG TIP(S) IS (ARE) LIGHT GREY.

1. Refer to ENGINE SLOWS DOWN OR STOPS AT HIGH RPM and check items listed.

2. Check spark plug heat range.

- Spark plug heat range is too high. Replace by Bombardier's recommended spark plug (refer to

TECHNICAL DATA).

3. Check if air intake silencer leaks.

- Air surplus coming from opening(s) located between halves. Seal.

4. Check carburetor adapter collars.

- Loose collar(s). Tighten.

5. Check carburetor adapter(s).

- Cracked or deformed adapter(s). Replace.

6. Check if primary compression leaks.

- Primary compression leaks. Perform leak down test and repair as necessary.

mmr2005-008 39