Perhaps we have to read the AHMRA rules
12.1.3 Historic 250: Certain 126-250cc machines built up to and including the 1977 model year that made up the first generation long-travel motorcycles. Eligible machines include:
1975-77 Bultaco Pursang, Frontera, Alpina 250, to include the 1977 MK10 Pursang
1975-77 Can-Am MX, TNT and Qualifier 175-250, up to MX3 (MX4 and later models see the Gran Prix classes)
1975-78 CZ 250 Falta Replica
1978 Harley-Davidson MX250
1975-77 Honda CR, MT, MR, XL 175-250
1975-76 Husqvarna CR, WR 250 and 1977 WR 250. 1977 Husqvarna CR/OR models are allowed, with fork travel limited to 9 inches. Otherwise, see GP 250.
1975-77 Kawasaki KX, KLX, KD, 175-250. 1978 Kawasaki KX250A4 (exceptional performance of this model may move it to the GP class).
1975-77 Maico MC, AW 250. 1977 model AW 250 must comply with the Historic class suspension limits.
1975-77 Montesa King Scorpion & Cappra VR 250 V-75, VA & Enduro 250H. VB, 1977 & 1978 models only; no later-model components, including swingarm. All later model Montesas, see GP classes.
1975-77 Ossa Phantom & Desert Phantom 250, up to GPIII model. 7. Ossas equipped with the “Bolger” rear suspension are allowed in the Historic class, provided that the suspension travel limits are met.
1975-77 Penton-KTM 175-250. 1977 models must meet the Historic Class suspension limits. (1978 Penton/KTM is not a like-design model. See GP classes.)
1975-76 Puch 250 MX (twin-carb Harry Everts replica)
1975-77 Suzuki RM, TM, PE 175 & 250
1975-77 Yamaha MX, YZ, DT, IT 175-250
Noel