Youth 51cc Stock Class approved 2002 models
| KTM | KTM | KTM | KTM | KTM | KTM | WASP | |
| YEAR | 2002 | 2002 | 2002 | 2002 | 2002 | 2002 | 2002 |
| MODEL | 50 Mini Adventure O.I. | 50 Mini Adventure | 50 JR Adventure | 50 SR Adventure | SX PRO JR LC | SX PRO SR LC | SR |
| BORE | 39.5mm | 39.5mm | 39.5mm | 39.5mm | 39.5mm | 39.5mm | 39mm |
| STROKE | 40.0mm | 40.0mm | 40.0mm | 40.0mm | 40.0mm | 40.0mm | 41.7mm |
| DISPLACEMENT | 49cc | 49cc | 49cc | 49cc | 49cc | 49cc | 49.8cc |
| CYLINDER LINER | Cast Iron | Cast Iron | Cast Iron | Cast Iron | Plated | Plated | Plated |
| CARBURETION | 12mm Dell'Orto | 14mm Dell'Orto | 14mm Dell'Orto | 14mm Dell'Orto | 14mm Dell'Orto | 19mm Dell'Orto | 19mm Dell'Orto |
| FRONT SUSPENSION | 4.5" Conventional | 4.5" Conventional | 5.3" Conventional | 6.9" Conventional | 5.3" Marzocchi 32 | 6.5" Marzocchi 32 | 6.3" EBR |
| REAR SUSPENSION | 7.3" Single |
7.3" Single |
9.2" Single |
7.5" Single |
7.87" Single WP | 7.3" WP Suspension | 6" IMCA ADJ |
| WHEELBASE | 35.8" | 35.8" | 35.8" | 40.0" | 36.0" | 40.0" | 39.25" |
| WHEEL SIZE (F) | 10" | 10" | 10" | 10" | 10" | 10" | 10" |
| WHEEL SIZE (R) | 10" | 10" | 10" | 10" | 10" | 10" | 10" |
| OVERALL LENGTH | 51" | 51" | 51" | 54.5" | 51" | 54.75" | 55" |
| SEAT HEIGHT | 21.8" | 21.8" | 24" | 26.5" | 24" | 26.6" | 26.25" |
| Class 1 Stock 4-6 |
Yes | Yes | Yes | No | Yes | No | No |
| Class 2 Stock 7-8 |
Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Class 3 Stock 4-8 |
Yes | No | No | No | No | No | No |
| POLINI | POLINI | HUSQVARNA | HUSQVARNA | HUSQVARNA | COBRA | COBRA | |
| YEAR | 2002 | 2002 | 2002 | 2002 | 2002 | 2002 | 2002 |
| MODEL | X1 Works | X3 Works | CR 50 J | CR 50 S | CR 50 SLC | CM-50 | King |
| BORE | 40mm | 40mm | 39mm | 39mm | 39mm | 39mm | 39mm |
| STROKE | 39.2mm | 39.3mm | 41.7mm | 41.7mm | 41.7mm | 41.7mm | 41.7mm |
| DISPLACEMENT | 49cc | 50cc | 49.8cc | 49.8cc | 49.8mm | 49.8cc | 49.8cc |
| CYLINDER LINER | Alloy | Nikasil | Nikasil | Nikasil | Nikasil | Nikasil | Nikasil |
| CARBURETION | Dell'Orto 14mm | Dell'Orto 19mm | Dell'Orto 14mm | Dell'Orto 19mm | Dell'Orto 19mm | ACER 14mm | DEL 19mm |
| FRONT SUSPENSION | Hydraulic 5" | Hydraulic 5" | 5.51" Hydraulic Telescopic | 6.69" Hydraulic Telescopic | 6.69" Hydraulic Telescopic | 5.5" Conventional Hydraulic | Inverted Cobra 8.75" |
| REAR SUSPENSION | Hydraulic 7" | Hydraulic 7" | 7.87" Single Shock Paoli | 8.86" Single Shock Paoli | 8.27" Single Shock Paoli | 7.5" Cobra Hydraulic w/ remote reservoir | Ohlins with Reservoir 9.75" |
| WHEELBASE | 35.5" | 40.6" | 35.625" | 41" | 40.34" | 35.75" | 38.5" |
| WHEEL SIZE (F) | 10" | 10" | 10" | 10" | 10" | 10" | 10" |
| WHEEL SIZE (R) | 10" | 10" | 10" | 10" | 10" | 10" | 10" |
| OVERALL LENGTH | 51.5" | 54.8" | 51.5" | 55" | 55.5" | 51" | 53.5" |
| SEAT HEIGHT | 24" | 28" | 24" | 26" | 27" | 23.875" | 25.5" |
| Class 1 Stock 4-6 |
Yes | No | Yes | No | No | Yes | No |
| Class 2 Stock 7-8 |
Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Class 3 Stock 4-8 |
No | No | No | No | No | No | No |
| LEM | LEM | BETA | DI BONITO | YAMAHA | SUZUKI | |
| YEAR | 2002 | 2002 | 2002 | 2002 | 2002 | 2002 |
| MODEL | LX2 | LX3 | Pro Race | 10-10 J | PW50 Oil Injected | JR-50K2 Oil injected |
| BORE | 39mm | 39mm | 40mm | 39mm | 40mm | 41mm |
| STROKE | 41.7mm | 41.7mm | 40mm | 41.8mm | 39.2mm | 37.8mm |
| DISPLACEMENT | 49.8cc | 49.8cc | 50.2cc | 49.8cc | 49cc | 49cc |
| CYLINDER LINER | Chromium | Chromium | Iron | Aluminum | Steel | Iron |
| CARBURETION | Dell'Orto PHBN14MS 14mm | Dell'Orto PHBG19BS 19mm | Dell'Otro PHB619BS 19mm | Dell'Orto 14mm | YM12 Mikuni | VM 2SC Mikuni |
| FRONT SUSPENSION | 140mm Hydraulic Marzocchi | 170mm Hydraulic Marzocchi | Hydraulic 32mm 5.8" | 2.5" Mech. | 60mm Telescopic | 70mm/2.8" Telescopic-Coil, w/2-way Adjust |
| REAR SUSPENSION | 140mm Hydraulic Paioli | 190mm Hydraulic Paioli | Mono Shock Hydraulic 8.8" | Mono Shock Hydraulic 2.5" | 50mm Unit Swing | 52mm/2" Swingarm, Twin Shock, Coil Spring, w/2-way adjust |
| WHEELBASE | 35.82" | 38.78" | 38.00" | 38.00" | 33.7" | 33.9" |
| WHEEL SIZE (F) | 10" | 10" | 10" | 10" | 10" | 10" |
| WHEEL SIZE (R) | 10" | 10" | 10" | 10" | 10" | 10" |
| OVERALL LENGTH | 51.18" | 53.54" | 53.7" | 53" | 49" | 50.6" |
| SEAT HEIGHT | 23.82" | 26.57" | 27.5" | 24" | 19.1" | 18.9" |
| Class 1 Stock 4-6 |
Yes | No | No | No | Yes | Yes |
| Class 2 Stock 7-8 |
Yes | Yes | Yes | Yes | Yes | Yes |
| Class 3 Stock 4-8 |
No | No | No | No | Yes | Yes |