KIWI RIDER 08 2018 VOL.1 | Page 67

Bill Ivy gets the Yamaha 250-4 airborn in the Isle of Man in 1968 Mike Pero on a TZ350 Yamaha in 1982 1968 Yamaha 250-4 Unfamiliar sight of Agostini on a Yamaha In 1974 Agostini switched his allegiance from MV Agusta to Yamaha and the two-strokes. The following year he beat Phil Read’s MV Agusta into second place in the championship, giving Yamaha the first two-stroke victory in the 500cc World Championship. From then on 500 grids were almost totally dominated by two-strokes. The only major factory to hold out was Honda, who continued to field the complex oval-piston, eight valve, NR500 four-stroke. Eventually Honda capitulated and joined the two-stroke ranks too. From 1977 on there were no four- strokes on the 500cc class grids. The most significant aspect of the two-stroke revolution was the availability of relatively inexpensive race machines being made available for private owners. This stimulated the smaller classes, particularly the 250 and 350cc classes, into fiercely competitive racing which would eventually spread to the 500 class. The first Yamaha 250 production racer was the TD1-C of 1967. By 1970 updated versions filled nine of the first ten places in the 250 World Championship. The riders included Rod Gould, Kel Carruthers, Kent Anderson, Jarno Saarinen, and Chas Mortimer. The accessibility of competitive racing machinery led to other advantages for the sport. The nature of two-stroke engine power forced an overdue reassessment of tyre, chassis and suspension technology. > Sharing your passion facebo ok.com /Caffein eAndCla ssics