Simplify the following text for a Grade 6 native English-speaking person.
Original: Herbert James ` Burt ' Munro , ( Bert in his youth ) ( 25 March 1899 -- 6 January 1978 ) was a New Zealand motorcycle racer , famous for setting an under-1000cc world record , at Bonneville , 26 August 1967 .
Simplified: Burt Munro ( 25 March 1899 â `` 6 January 1978 ) was a motorcycle racer from New Zealand .