1980 Ski-Doo Shop Manual, Page 215Get this manual
SECTION 04 SUB-SECTION 06 (SPARK PLUGS)
EXPLANATION OLD SYSTEM
Example: X4 X6 For Marine Engines, resistant to seawater Electrodes with Platinum Tips Silver Center Electrode Wide-Gap Electrodes.060" Wide-Gap Electrodes.044 11 Wide-Gap Electrodes.060 11
EXPLANATION NEW SYSTEM
Example:
X wide gap .044" (1.1 mm) wide gap .060" (1.5 mm) special shell or
GERMANY
electrode designs
Thread Reach
Thread Reach:
ER Shielded, water-proof; built-in
burn-off resistor
Thread reach -.460" standard
electrode
Plugs for 2-cycle engines Electrodes of precious metals Suppressor resistor, 5000 ohms,
builtin
Thread reach .460" extended tip electrode
Thread reach
electrode
ill regular
Silver ground electrode Standard type Semicovered front electrode