1970-1979 Ski-Doo Snowmobiles Service Manual, Page 32Get this manual
PERIODIC MAINTENANCE AND TUNE-UP Table Engine IGNITION TIMING SPECIFICATIONS Indirect Timing BTDC'
Direct Timing BTOC'
245(1976)" 245 (1975)'" 247 248,249 250 292 (1970-1971) 292,302 (1972) 294 300 302 305 304,343 (1978) 335 337 338 340(1970) 340(1971) 343(1972) 343(1973) 343 345'" 345(1978) 346(1973)" 396(1973) 346,396(1974) 354"454399,440(1970,1971) 401,434,435 (1972) 401 434,4404 435 436" 440(1975) 440(1978-1979) 444 503