[2] Kasper won the 1982 European Under-21 Championship at the Rottalstadion in Pocking, West Germany.

[3] He then joined Hackney Hawks in the British leagues and rode for them in 1982 and 1983.

[5] On 25 July 1998, he won the Continental Final, which formed part of the 1999 Speedway Grand Prix Qualification.

[6] Kasper rode in the United Kingdom for the Hackney Hawks from 1982 until their closure the following season at the end of 1983.

His father Antonín Kasper Sr. also appeared in Speedway World Championship finals.