1970-1979 Ski-Doo Snowmobiles Service Manual, Page 30Get this manual
PERIODIC MAINTENANCE AND TUNEUP Table SPARK PLUG APPLICATION Champion Gold Standard Palladium
K-9 K-9 RM-2 L-81 K-8G K-8G N-2G L-6G
Bosch Standard
M175Tl M225Tl W280MZ2 W240Tl W280S1S W260S1S
Elan 250; Olympique 300 (299 engine) Olympique 335, 440 (1973) Olympique 300 (1976) T'NT FIA, T'NT RN, T'NT 440(1973) (14mm heads)and RN 340 Elan 250Twin and Deluxe to 1977 Olympique 300T, 340, 399, T'NT 399 Olympique 300 Twin (1978and later) Olympique 340, 340E (1978 and later) Citation 300 (1978 and later) Everest 340, 340E (1978 and later) T'NT340 (1978) Blizzard 6500,7500,9500 Blizzard 5500 Everest 440, 440E; T'NT 440 LlC Everest 444 LIe