2021 Production Class Clarification Chart

Revised 3.31.21

2021 ATVMX Production Stock Class Chart

ITEMS IN QUESTION 
Yes: Allowed to change or modifyNOTES
No: NOT allowed to change or modify; must remain OEM
BODY AND CONTROLS
HandlebarsYes
Hand GuardsYes
Clutch LeverYes
GripsYes
BumperYes
Grab BarYes
Steering StabilizerYes
Safety ReflectorsYes 
Clutch CablesYes 
PlasticsYes 
Seat CoversYes 
Seat Foam or PanYes 
Headlight and Brake LightYes 
Skid PlatesYes 
Powder Coat / PaintYes 
Parking BrakeYes 
Handlebar RisersYes 
Steering Stem Yes 
Steering Flag No 
Bar ClampYes 
Foot PegsYes 
Heal Guards Yes 
Shift LeverYes 
Throttle HousingYesIncludes switching to twist
DecalYes 
Radiator Shrouds or Louvers Yes 
Add Foam (Mud Inhibitor)Yes 
BRAKES  
Brake Master CylinderNo 
Brake PadsYes 
Brake Rotors Yes 
Brake LinesYes 
Pedal / Levers Yes  
Rear Brake Hub No 
ENGINE   
Internal Engine Modification NoIncluding engine blue printing and crank balancing; Must use OEM replacement parts of same make and model
Cylinder Bore ReplatingYes 
ExhaustNoWhole or part; May remove emissions pieces
MufflerNo 
Timing PlugsYes 
Clutch PlatesYesMust maintain OEM shape design and material
Clutch Arm No 
ECUNoFlashing OEM ECU permitted
CarburatorNoJetting permitted
Leak Jet No 
Fuel ScrewNo 
Carb Float BowlNo 
Throttle BodyNo 
Intake SpacerNo 
Reed Valves and AssemblyNo 
Oil Injection SystemNoMust use oil
ECV (Exhaust Control Valve)No 
Cherry Bomb (Suz)No 
Clutch Cover No 
Ignition CoverNo 
CHASSIS  
Ti BoltsNoUnless sold on production quad
Ceramic BearingsNoUnless sold on production quad
BearingYesMust maintain OEM shape, design, and material
Air Intake BootNo 
Air BoxNoMay remove lid
Air Box Vent TubesYes 
Air FilterYes 
Air Filter ScreenNoMay not remove
Oil CoolerNo 
Gas Tank Thermal CoverYes 
Countershaft Cover / Case Saver Yes 
Drain Bolts and Filler PlugsYescosmetic only
Radiator HosesYes 
RadiatorNo 
Radiator FanNo 
Wiring HarnessYes 
ECU LocationYesMay move  
Capacitor / CondenserYesMay add
Solder Fuel Pump ConnectionYes 
Breather BoxYesMay move vent lines 
BatteryYes 
DRIVE  
ChainsYes 
SprocketsYes 
Chain GuidesYes 
Chain Rollers/ Sliders Yes 
Sprocket HubNo 
FRAME  
Frame NoMaterial may be added for strength
Subframe NoMaterial may be added for strength
Subframe Support RailsYes 
SUSPENSION  
Internal ModificationsYesRespring and revalve only allowed;  Compressed and extended length must maintain OEM spec.
Shock Springs Yes 
Shock ValvingYes 
A-ArmsNo 
SwingarmNo 
Linkage No 
BushingsYesMust remain same material as OEM
WHEELS AND AXLE  
WheelsYes 
TiresYes 
Front HubsNo 
Front SpindlesNo 
Rear Hubs No 
AxleYes 
REQUIRED  
Kill switchYes 
NerfbarsYes