Yoshi and Kiyo both entered in this years Catalina Grand prix (2010). Both entered in the lightweight vintage class, and Kiyo took 1st place!!
Here's a little history on the bikes :
1964 TD1 motor
YDS2M chasis ( steering raked 3 degrees)
Catalina works racer replica
1956 Triumph T20 Tiger cub
head modified, bigger port, bigger head. Original racing piston. High cam shaft (original)
650 front end
Bud Ekins raced the same Triumph in the 50s. (same model)
The Yamaha first appeared in 1958 at the Catalina Grand Prix being ridden by Fumio Itoh. He took 6th even though he fell twice. It was also being ridden by Roxy Rockwood.
Here are some photos of the race, bikes and track: