The 125cc MAX engine is the original MAX engine that started it all. Many consider this to be the premier class in MAX Challenge competition. This same engine is used for two classes, Senior MAX for drivers 15 and up, and MAX Masters for drivers 32 years-of-age and older.
*MSRP is $3,565 for complete engine package and $2,244 for and engine-only package.
Technical Specifications
| Age | 15+ years |
| Race Class | National – International |
| Horsepower | 28.5 hp (21 kW) at 11,500 rpm |
| Maximum Torque | 15.5 ft./lb. (21 Nm) at 8,750 rpm |
| Weight | Bare engine: 26.5 lbs (12 kg), with complete power pack: 58.6 lbs (23.6 kg) |
| Special features | Cylinder with pneumatic timed exhaust valve |
| Power Pack | Silencer, carburetor, fuel pump, engine, exhaust system, radiator, battery, battery box, cable harness, start button, ON/OFF switch |
| Chassis compatibility | wheel base up to 1,050 mm |