KITTY KAT & 120 CLASSES
KITTY KAT
AGES 4 - 7
This class is for children with little to no racing experience & is designed to sharpen racing skills and build confidence!
The Kitty Kat class races on the MSX starting line, not on the big track.
Full class rules on page 23 of the MSX Rulebook.
STOCK 120
AGES 4 - 7
Riders 4 - 7 years old, must turn 4 years old before December 1 of the season year.
See ISR Rulebook page 38 for in-depth rules.
120 CHAMP
AGES 6 - 12
Riders 6 - 12 years old, must turn 6 years old before December 1 of the season year.
See ISR Rulebook page 41 for in-depth rules.
200 CLASSES
STOCK 200 6 - 8
AGES 6 - 8
Stock 200cc, ages 6 - 8. Shocks and skis may be changed; aftermarket shocks are permitted but cannot exceed OEM shock length.
No studs allowed.
See ISR Rulebook page 31 for in-depth rules.
STOCK 200 9 - 12
AGES 6 - 12
Stock 200cc, ages 9 - 12. Shocks and skis may be changed; aftermarker shocks are permitted but cannot exceed OEM shock length.
No studs allowed.
See ISR Rulebook page 31 for in-depth rules.
PRO 225
AGES 7 - 12
NEW CLASS
Pro 225 class to use only Tillotson racing engine. Model TPP - 225RS. Shocks and skis may be changes; aftermarket shocks permitted but cannot exceed OEM shock length.
See ISR Rulebook page 34 for in-depth rules.
TRANSITION & JUNIOR CLASSES
TRANSITION 8 - 10
AGES 8 - 10
600cc stock race sled, minimum of one (1) model year old. NO studs; maximum track lug height of 1.75". ECU rev-limited to 6500 RPM. Throttle restricted to 50% max. Exhaust valves blocked shut. Primary clutch engagement at 4400 max RPM. Sunoco Surge 105 fuel.
See ISR Rulebook page 27 for in-depth rules.
TRANSITION 11 - 13
AGES 11 - 13
600cc stock race sled, minimum of one (1) model year old. NO studs; maximum track lug height of 1.75". ECU rev-limited to 6500 RPM. Throttle restricted to 50% max. Exhaust valves blocked shut. Primary clutch engagement at 4400 max RPM. Sunoco Surge 105 fuel.
See ISR Rulebook page 27 for in-depth rules.
TRANSITION GIRLS
AGES 8 - 12
600cc stock race sled, minimum of one (1) model year old. NO studs; maximum track lug height of 1.75". ECU rev-limited to 6500 RPM. Throttle restricted to 50% max. Exhaust valves blocked shut. Primary clutch engagement at 4400 max RPM. Sunoco Surge 105 fuel.
See ISR Rulebook page 27 for in-depth rules.
JUNIOR GIRLS
AGES 9 - 13
600cc stock race sled, minimum of one (1) model year old. Maximum track lug height of 1.75". ECU rev-limited to 6500 RPM. Throttle restricted to 50% max. Exhaust valves blocked shut. Primary clutch engagement at 4400 max RPM. Holeshot function must be disabled. Sunoco Surge 105 fuel.
See ISR Rulebook page 28 for in-depth rules.
JUNIOR 10 - 13
AGES 10 - 13
600cc stock race sled, minimum of one (1) model year old. Maximum track lug height of 1.75". ECU rev-limited to 6500 RPM. Throttle restricted to 50% max. Exhaust valves blocked shut. Primary clutch engagement at 4400 max RPM. Holeshot function must be disabled. Sunoco Surge 105 fuel.
See ISR Rulebook page 28 for in-depth rules.
JUNIOR 14 - 17
AGES 14 - 17
Open to riders aged 14-17; if the rider turns 18 during the season, they may continue. A restricted throttle that allows no more than a 50% throttle opening must be properly installed.
See ISR Rulebook page 28 for in-depth rules.
BEGINNER & SPORT
BEGINNER
AGES 14+
Minimum age of 14; must turn 14 years old before December 1 of the season year. Entry-level class for new riders with under 1 year of experience on a race sled. Riders can participate in this class for (1) season. 600cc stock race sleds, minimum of (1) model year old. Sport Lite Class Rules.
In-depth rules start on page 15 of the ISR Rulebook.
SPORT LITE
AGES 14+
Minimum age of 14; must turn 14 years old before December 1 of the season year. This class is for riders with previous race experience and is designed to bridge the gap between Junior/Beginner and Sport. Riders may be moved up to Sport at the Race Director's discretion.
In-depth rules start on page 15 of the ISR Rulebook.
SPORT
AGES 14+
Minimum age of 14; must turn 14 years old before December 1 of the season year. This class is for riders with previous race experience.
In-depth rules start on page 15 of the ISR Rulebook.
PRO & ADULT CLASSES
PRO AM WOMEN
AGES 14+
Minimum age of 14; must turn 14 years old before December 1 of the season year. Women with previous racing experience. Payout class to the top 3 finishers - based on the total number of race entries, paid at the podium.
In-depth rules start on page 15 of the ISR Rulebook.
PRO LITE
AGES 16+
Minimum age of 16; must turn 16 years old before December 1 of the season year. Aftermarket cans/silencers allowed. Stock OEM Y-pipe and main pipe required, unmodified. Aftermarket shocks, bearings, skis and handlebars allowed. Payout class to the top 3 finishers, based on entries.
In-depth rules start on page 15 of the ISR Rulebook.
PRO
AGES 16+
Minimum age of 16. Aftermarket cans/silencers allowed. Stock OEM Y-pipe and main pipe required, unmodified. Aftermarket shocks, bearings, skis and handlebars allowed. Headlights must remain functional but do not need to be covered. Payout class to the top 3 finishers, based on entries.
In-depth rules start on page 15 of the ISR Rulebook.
PRO AM PLUS 30
AGES 30+
Minimum age of 30; must turn 30 years old before December 1 of the season year. Aftermarket cans/silencers allowed. Stock OEM Y-pipe and main pipe required, unmodified. Aftermarket shocks, bearings, skis and handlebars allowed. Payout class to the top 3 finishers, based on entries.
In-depth rules start on page 15 of the ISR Rulebook.
40+
AGES 40+
Minimum age of 40; must turn 40 years old before December 1 of the season year. Aftermarket cans/silencers allowed. Stock OEM Y-pipe and main pipe required, unmodified. Aftermarket shocks, bearings, skis and handlebars allowed. Payout class to the top 3 finishers, based on entries.
In-depth rules start on page 15 of the ISR Rulebook.
MICHIGAN SNOCROSS
RULEBOOK
The Michigan Snocross Rulebook contains the regulations for competition, including rider eligibility, class requirements, safety equipment, sled requirements, race procedures, conduct and more. Michigan Snocross follows ISR Class Rules & Specs unless otherwise outlined in the Michigan Snocross Rulebook.
All racers and race teams are responsible for understanding and following the current Michigan Snocross Rules & Code of Conduct.