In the annals of American motorcycle racing, there is hardly any feat more celebrated–no story more recounted–than Kenny Roberts’ epic win on the famed TZ750 flat tracker at the 1975 Indy Mile. It was an amazing accomplishment befitting of a living legend nicknamed “The King.”
But, there is one aspect of that historic event that is often overlooked, or not even known, and it’s a detail that fades more and more as time goes by.
The Yamaha TZ750 was actually not the first or only multi-cylinder, two-stroke 750cc flat tracker to compete during that era. In fact, that screaming, bumblebee-liveried bike, with Kenny Roberts in the saddle, wasn’t even the first multi-cylinder, two-stroke 750cc flat tracker to win an AMA-sanctioned mile flat track races, either.
That honor goes to Kawasaki, Scott Brelsford, and none other than Erv Kanemoto.
Over the span of three years prior to the 1975 racing season, Kanemoto–who, of course, went on to become world famous as a tuner and crew chief for Grand Prix World Champions Freddie Spencer, Eddie Lawson, Wayne Gardner, John Kocinski, Kenny Roberts Junior, Max Biaggi and several other well-known riders–had been working on a 750cc Kawasaki H2 three-cylinder two-stroke flat tracker.
Unlike the TZ750, which was conceived from the beginning as a production racebike with a liquid-cooled four-cylinder engine, the Kawasaki H2 was a production streetbike. Also known as the “Mach IV,” the H2 was an air-cooled triple that had a reputation in its day for being the biggest, baddest two-stroke street-going motorcycle of all time. To this day, the H2 is equally revered and feared by those who remember it.
In a Herculean effort to conquer the rioting hordes of Harley-Davidson XR750 flat trackers that were virtually unbeatable in AMA Class C flat track racing, Kanemoto shoehorned the Kawasaki triple into a Champion racing frame. He actually built two bikes, both with Ceriani front forks, spoked Akront aluminum front rims and, oddly enough, cast aluminum “mag-type” rear wheels.
Riders? In 1975, Yamaha had decided to go with just Roberts as its sole rider, which meant that Don Castro was out of a job. So, Kanemoto hired Castro to ride one of his beastly creations and for the second bike, Kanemoto hired Scott Brelsford, the younger brother of 1972 AMA Grand National Champion Mark Brelsford. Castro rode bike #11 and Brelsford rode #19.
Kanemoto, Castro, and Brelsford showed up at the AMA Regional Championship Stockton Mile in California on July 6, 1975. Castro was unable to qualify for the Expert Main, but Brelsford did qualify, and he also won the race.
It was the first official win for a two-stroke in AMA Expert mile flat track competition, and it happened more than a month prior to Kenny Roberts’ celebrated Indy Mile win on his Yamaha TZ750, which occurred on August 23, 1975.
In fact, it’s been said that the two Kawasaki flat trackers built by Erv Kanemoto are actually what compelled Yamaha tuner Kel Carruthers to have a Champion frame built that would accommodate the inline-four-cylinder, two-stroke engine from Yamaha’s TZ750 (OW31) road racer.
A month prior to Brelsford’s win at the Stockton Mile, Kanemoto, Castro, Brelsford, and the two Kawasaki H2 flat trackers competed at the San Jose Mile, which was held on May 18, 1975. Carruthers, Roberts, and the Yamaha TZ750 flat tracker were also there, but none of the two-strokes did very much. Roberts finished fifth, and Brelsford was 18th–his #19 Kawasaki had snapped a rod and also suffered a cracked exhaust pipe during the race. Castro was unable to qualify, so he and his #11 H2 didn’t race in the Main.
As was becoming the accepted norm, the two-stroke bikes were slow in the corners. In contrast, the low-end torque of the four-stroke twins enabled them to pull away off the corners, only to have the two-strokes catch up halfway down the straightaways, due to their eyeball-flattening acceleration. There was a 15-mph speed difference between the four-stroke twins (125 mph) and the two-stroke triples and fours (140 mph) on the straightaways.
Castro and Brelsford attempted to qualify the H2 flat trackers at Terre Haute, Indianapolis, and Syracuse, but the powerband on the bikes was even more of a lightswitch than it was on Roberts’ TZ, and the two Kawasakis just would not hook up in the dirt. As a result, Brelsford qualified for just one of the mile races, and ironically, it was at the Indy Mile, the very same race that Roberts ended up winning in epic fashion on the TZ750.
Make no mistake, Kenny Roberts’ win at the Indy Mile on August 23, 1975, was legendary and should be recalled for all eternity but, in actuality, it was not a first. That distinction goes to Scott Brelsford at the Stockton Mile, thanks to the brilliance of Erv Kanemoto.