PRO AM

Open to Pro, Pro Lite, Sport,Sport Lite.

MUST BE 16 to Race PRO classes

Pro Am and Pro Lite payout.
We will return the entry fee for the Pro riders.
Example 8 X $90.00 $720.00 purse we will pay out. If 8 or less 3 places 9 or more it will go to 5 places payout.
Any Bonus Money will be pro-rated if there are 5 or less sleds entered in a class.
Example $1,000.00 added purse total purse will be $1720.00 based on 6 sleds entered.

All Pro-Lite sleds may use a commercially available aftermarket can/silencer. The silencer used may not be constructed of titanium or carbon fiber. The main exhaust system must remain stock and unaltered. This includes Y pipe, expansion chamber, pulse charger. No alterations to these components are allowed, to utilize an aftermarket can/silencer. Carbon fiber or Titanium materials are not allowed in construction of these components. 2. Tabs or brackets may be welded to the external body of the original exhaust system to facilitate the installation of the aftermarket can/silencer.

PRO LITE

Open to Pro, Pro Lite, Sport,Sport Lite

MUST BE 16 to Race PRO classes

Pro Am and Pro Lite payout.
We will return the entry fee for the Pro riders.
Example 8 X $90.00 $720.00 purse we will pay out. If 8 or less 3 places 9 or more it will go to 5 places payout.
Any Bonus Money will be pro-rated if there are 5 or less sleds entered in a class.
Example $1,000.00 added purse total purse will be $1720.00 based on 6 sleds entered.

All Pro-Lite sleds may use a commercially available aftermarket can/silencer. The silencer used may not be constructed of titanium or carbon fiber. The main exhaust system must remain stock and unaltered. This includes Y pipe, expansion chamber, pulse charger. No alterations to these components are allowed, to utilize an aftermarket can/silencer. Carbon fiber or Titanium materials are not allowed in construction of these components. 2. Tabs or brackets may be welded to the external body of the original exhaust system to facilitate the installation of the aftermarket can/silencer.

SPORT

Open to riders 14 and up.

Up to 600cc liquid 2- stroke or approved four-stroke.

SPORT LITE

Open to riders 14 and up.

Up to 600cc liquid 2- stroke or approved four-stroke.

WOMEN

Open to all Women 14 and up

• 14 to 17 girls must run these.
• 50% Throttle Block Kit including Calibration tool.
• Studs are allowed in this class.

Minimum age of 14 for trail class.

Junior Girls 9-13

• Arctic Cat snowmobiles may be the current year offering and do not need to conform to the one-year rule for the 2021 season.
• Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM)( Exception Polaris 2020 and older sleds can be 6600)
• Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand.
• The exhaust valves will be blocked in the shut position
• Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM) (measured with secondary Sheave movement)
• Studs are allowed in this class.
• Rider, running board blocks can be used.
• Pre Heat “hole shot” function must be disabled
• Please check complete Junior Novice rules on MWSS website under ISR SNOCROSS JUNIOR CLASSES

Junior Girls 14-17

• 50% Throttle Block Kit including Calibration tool.
• Studs are allowed in this class.
• Please Check ISR Rules for complete list of rules ISR Rules
• Up to 600cc liquid 2- stroke or approved four-stroke.

Plus 30

• Plus 30 Years old
• Please Check ISR Rules for complete list of rules ISR Rules
  

Plus 40

• Plus 40 Years old
• Please Check ISR Rules for complete list of rules ISR Rules
• Minimum age of 14 for trail class.

Novice

• This class is for new riders on race sleds or trail sleds 600cc or under
• Riders with less then a years experience racing can enter this class this class is an entry level class.
• ISR will not sanction or approve any class that features two-stroke snowmobile engines with displacement over 600 cc.
• Please Check ISR Rules for complete list of rules ISR Rules
• Up to 600cc liquid 2- stroke or approved four-stroke.
• Minimum age of 14 for trail class.
  

Juniors 10-13 (2 )Same class as Junior1 just another chance for the kids to race.

• Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM).
• Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand.
• The exhaust valves will be blocked in the shut position.
• Primary clutch engagement will be 4000 Max RPM. (measured with secondary Sheave movement).
• Studs are allowed in this class.
• Pre Heat “hole shot” function must be disabled
• Please Check ISR Rules for complete list of rules ISR Rules

The rules committee may at any time during the racing season, review the restrictions of the designated models if a brand is dominating the class. Stock legal production 600 cc Super Stock race snowmobileswill be the formatforJunior Novice classes. These sleds will bedeveloped with specific manufacturer-based modifications andrestrictions. The snowmobiles will be raced as produced with only the following changes. 1. This class will follow all the rules for the stock-based snow cross class. 2. Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM)( Exception Polaris 2020 and older sleds can be 6600) 3. Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand. 4. The exhaust valves will be blocked in the shut position. 5. Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM) (measured with secondary Sheave movement) 6. Rider, running board blocks can be used. 7. Studs are allowed in this class. 8. 1 ¾” tracks are legal for all sleds. 9. The sleds listed below are also approved to continue to run in the class following the stock – based Sno cross class rules and the limitations listed below. 10. Pre-Heat “hole shot” function must be disabled. • 2010 -2014 Arctic Cat 500 Sno Pro with 50% throttle opening installed Primary clutch engagement will be 5000 Max RPM. (Measured with secondary sheave movement) • 2014-2019 4000 Series with 50% throttle opening installed. Primary clutch engagement will be 5000 Max RPM. (Measured with secondary Sheave movement) • Ski-Doo MXZ 600 -Limited Division • Ski-Doo MXZ TNT- Limited Division • 2010-2014 MXZ 600 (Non-HO) Sport and 2010-2012 MXZ (Non-HO) TNT with approved performance limiting kit

Transition 8-10

• Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) (Exception Polaris 2020 and older sleds can be 6600 RPM)
• Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand.
• The exhaust valves will be blocked in the shut position.
• Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM (measured with secondary Sheave movement)
• NO Studs are allowed in this class
• Please check complete Transition rules on MWSS website under ISR SNOCROSS JUNIOR CLASSES ISR RULES

ALL SLEDS UTILIZED IN THIS CLASS MUST BE NON-CURRENT, OR A MINIUMN OF (1) ONE MODEL YEAR OLD. The rules committee may at any time during the racing season, review the restrictions of the designated models if a brand is dominating the class. The following parameters must be adhered to: 1. This class is to be run as the only class on the racetrack. Designated sleds may be run together. 2. The class is for drivers that are 8 years old and not yet 13 years old. (It is not open to younger or older drivers.) 3. The snowmobile models eligible must be designated by ISR and the Rules Committee. Stock legal production 600 cc Super Stock race snowmobileswill be the formatfor Transition classes. These sleds will bedevelopedwith specific manufacturer-based modifications andrestrictions. The snowmobiles will be raced as produced with only the following changes. 1. This class will follow all the rules for the stock-based snow cross class. 2. Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) 23-24 International Snowmobile Racing Rules Copyright 2023 SNO CROSS RACING COMPETITION Page | 26 (Exception Polaris 2020 and older sleds can be 6600 RPM) 3. Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand. 4. The exhaust valves will be blocked in the shut position. 5. Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM) (measured with secondary Sheave movement) 6. Rider, running board blocks can be used. 7. Programmable Tethers: Also, effective 1/3/2020 no competitor or mechanics in the transition class are allowed to possess a tether that is not programmed for the transition class when they are between their trailer-staging-racetrack-podium during any transition events or practice. If you are found with a non transition programed tether it is grounds for a DQ.

Transition 11-13

• Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) (Exception Polaris 2020 and older sleds can be 6600 RPM)
• Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand.
• The exhaust valves will be blocked in the shut position.
• Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM
• NO Studs are allowed in this class
• Please check complete Transition rules on MWSS website under ISR SNOCROSS JUNIOR CLASSES ISR RULES

ALL SLEDS UTILIZED IN THIS CLASS MUST BE NON-CURRENT, OR A MINIUMN OF (1) ONE MODEL YEAR OLD. The rules committee may at any time during the racing season, review the restrictions of the designated models if a brand is dominating the class. The following parameters must be adhered to: 1. This class is to be run as the only class on the racetrack. Designated sleds may be run together. 2. The class is for drivers that are 8 years old and not yet 13 years old. (It is not open to younger or older drivers.) 3. The snowmobile models eligible must be designated by ISR and the Rules Committee. Stock legal production 600 cc Super Stock race snowmobileswill be the formatfor Transition classes. These sleds will be developed with specific manufacturer-based modifications and restrictions. The snowmobiles will be raced as produced with only the following changes. 1. This class will follow all the rules for the stock-based snow cross class. 2. Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) 23-24 International Snowmobile Racing Rules Copyright 2023 SNO CROSS RACING COMPETITION Page | 26 (Exception Polaris 2020 and older sleds can be 6600 RPM) 3. Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand. 4. The exhaust valves will be blocked in the shut position. 5. Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM) (measured with secondary Sheave movement) 6. Rider, running board blocks can be used. 7. Programmable Tethers: Also, effective 1/3/2020 no competitor or mechanics in the transition class are allowed to possess a tether that is not programmed for the transition class when they are between their trailer-staging-racetrack-podium during any transition events or practice. If you are found with a non transition programed tether it is grounds for a DQ.

Transition Combined 8-12

• Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) (Exception Polaris 2020 and older sleds can be 6600 RPM)
• Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand.
• The exhaust valves will be blocked in the shut position.
• Primary clutch engagement will be 4000 Max RPM. (measured with secondary Sheave movement
• NO Studs are allowed in this class
• Please check complete Transition rules on MWSS website under ISR SNOCROSS JUNIOR CLASSES ISR RULES

ALL SLEDS UTILIZED IN THIS CLASS MUST BE NON-CURRENT, OR A MINIUMN OF (1) ONE MODEL YEAR OLD. The rules committee may at any time during the racing season, review the restrictions of the designated models if a brand is dominating the class. The following parameters must be adhered to: 1. This class is to be run as the only class on the racetrack. Designated sleds may be run together. 2. The class is for drivers that are 8 years old and not yet 13 years old. (It is not open to younger or older drivers.) 3. The snowmobile models eligible must be designated by ISR and the Rules Committee. Stock legal production 600 cc Super Stock race snowmobileswill be the formatfor Transition classes. These sleds will bedevelopedwith specific manufacturer-based modifications andrestrictions. The snowmobiles will be raced as produced with only the following changes. 1. This class will follow all the rules for the stock-based snow cross class. 2. Electronic control unit ECU will be reprogrammed with rev limit restrictions (rev limited to maximum 6500 RPM) 23-24 International Snowmobile Racing Rules Copyright 2023 SNO CROSS RACING COMPETITION Page | 26 (Exception Polaris 2020 and older sleds can be 6600 RPM) 3. Restricted throttle kit not to allow more than 50% throttle opening must be installed designated throttle kit part numbers will be supplied by brand. 4. The exhaust valves will be blocked in the shut position. 5. Primary clutch engagement will be 4000 Max RPM. (Exception Polaris 2020 and older sleds can be 4100 RPM) (measured with secondary Sheave movement) 6. Rider, running board blocks can be used. 7. Programmable Tethers: Also, effective 1/3/2020 no competitor or mechanics in the transition class are allowed to possess a tether that is not programmed for the transition class when they are between their trailer-staging-racetrack-podium during any transition events or practice. If you are found with a non transition programed tether it is grounds for a DQ.

120 Imp Stock 4 – 5

• These are classes for 4-12-year-old drivers.
• At times, regional or national rules may apply, but in any case, competitors will not be younger than 4 years of age.
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

120 Imp Stock 6 – 7

• These are classes for 4-12-year-old drivers.
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

120 Imp Stock 8 - 12

• These are classes for 4-12-year-old drivers.
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

Pro 206 6-12

• Briggs & Stratton motor
• Please Check ISR Rules for complete list of rules ISR Rules
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

Pro 206 8-12

• Briggs & Stratton motor
• Competitors must be 7 years of age with one year of driving experience. Drivers reaching 14 years of age during the season may finish the season in that class
• Please Check ISR Rules for complete list of rules ISR Rules
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

200 Stock 8-9

• Stock 200's Rules. Factory 6000 rpm rev limiter must be intact and functional.

May move up to and run 200 Stock 10-12 and 200 Stock 6-12

120 Champ 6-12

• Stock 120: These are classes for 4-12-year-old drivers. Champ 120: These are classes for drivers aged 6-12. All other technical rules apply.
• In Champ classes, drivers must have at least one-year experience in 120/4 classes and be at least 7 years old through 14 years old. Drivers who attain the age of 15 during the scheduled season may complete the season.

120 Imp Stock 4 - 12

• These are classes for 4-12-year-old drivers.
• Helmets, upper body protection, shin guards, and above the ankle boots are required in all classes. 2. Mouth guards are mandatory in Sno-Cross and any other race over uneven terrain. Mouth guards must remain in place for the duration of the race.

200 Stock 10-12

Stock 200's Rules. Factory 6000 rpm rev limiter must be intact and functional.

May also run 200 Stock 6-12

Pro Ironwood

This will be available to Pro riders in Ironwood Race only.

This class will payout only the Ironwood purse advertised

Pro Ironwood

This will be available to Pro Lite riders in Ironwood Race only

This class will payout only the Ironwood purse advertised