| Engine | |
| Engine type | 420cc liquid-cooled dry-sump longitudinal OHV 4-stroke single cylinder |
| Bore and Stroke | 86.5 x 71.5 mm |
| Carburation | Keihin 24mm throttle body fuel-injection system |
| Ignition | Full-transistor with electronic advance |
| Displacement | 420cm cubed |
| Compression Ratio | 9.8:1 |
| Valve train | OHV |
| Intake valve:opens | 6 BTDC (at 1mm lift) |
| Intake valve:closes | 45 ABDC (at 1mm lift) |
| Exhaust valve:opens | 45 BBDC (at 1mm lift) |
| Exhaust valve:closes | 2 ATDC (at 1mm lift) |
| Lubrication system | Forced pressure and wet sump |
| Oil pump type | Trochoid |
| Air filtration | Oiled double urethane foam |
| Starter | Electric with recoil backup |
| Drive Train | |
| Transmission | 5 fwd/1 rev - auto clutch with electric shift (ESP) |
| Driveline | unique AP-type® torque-sensitive front limited-slip differential with switchable 2wd/4wd |
| Chassis/suspension/brakes | |
| Front suspension | Double wishbone |
| Rear suspension | Swingarm (trailing type) |
| Front brakes | Dual hydraulic disc |
| Rear brakes | Mechanical drum |
| Front tyres | 24 x 8-12 |
| Rear tyres | 24 x 10-11 |
| Dimensions | |
| Length | 2055mm |
| Width | 1172mm |
| Height | 1146mm |
| Wheelbase | 1249mm |
| Seat height | 822mm |
| Ground clearance | 170mm |
| Fuel capacity | 14 litres |
| Dry weight | 249kg |
| Other | |
| Available colours | Red or Olive Green* (available to special order) |
| Model ID | TRX420FM |
| Manufacturers warranty information | |
| 24 months | Coverage of defects in materials and workmanship. |

