The rivalry that existed between Yoshimura and Honda, in the late 1960s and into the 1980s, was basically “win at all costs”.
Pops Yoshimura and Mr. Honda were great racetrack rivals in Japan and Honda followed Yosh to the racetrack in the US where the competition for racetrack superiority continued. The rivalry between the two companies was so strong and heated that even years after Pops Yoshimura had passed away from cancer and Mr. Honda retired, it was a startling ‘Did I just see that?!’ moment when American Honda debuted their Supersport race bikes fitted with Yoshimura exhausts in the mid-1990s. It was a rare olive branch between the two warring companies.
Interestingly, that cut-throat attitude was never present when it came to Moriwaki and Honda. Hot rod parts house Moriwaki enjoyed a very collaborative relationship with Honda, as the two worked together and shared technology for over twenty years. This is interesting because basically Moriwaki is a direct off-shoot of Yoshimura Japan.
Moriwaki was started when ex-Yoshimura man Mamoru Moriwaki married Pops Yoshimura’s daughter. Together they started Moriwaki Engineering Company which was quickly taken under the wing of Honda. Honda and Moriwaki collaborated on many different projects, from Suzuka 8 Hour racers to, of course, the Moriwaki “Dream Fighter” MotoGP bike, powered by the Honda RC211 V5. They continue to work together today.
Moreover, American Honda purchased one of the early generation square-tubed aluminum rolling chassis from Moriwaki to use in the AMA Formula 1 class, fitted with their 1025cc superbike engine. After establishing the purchase toward the end of 1981, American Honda was informed that the FWS was on plan to be AH’s entry into the F-1 class in 1982. Thus the Moriwaki framed bike was moved from a front line entry to use by Robert Pietri and Steve Wise. In the above semi-rare image, one can see the Moriwaki-Honda 1000 (aluminum-frame) next to the RSC RS1000 (steel tube frame), Honda’s official Formula 1 entry in 1980-81. RSC (Racing Service Center) being the early version of HRC).
At this event, Loudon 1982, California dirt tracker Scott Pearson was given the opportunity to race the #95 RSC RS1000. Texan Steve Wise rode the #38 Moriwaki framed bike, both bikes using the Honda 1025cc Superbike engines. Scott’s long limbs required some help in the ergonomics department: notice the seat pads stacked up on the #95 bike to minimize the racer “crouch” to aid comfort.
Also in this photo are early 1980s American Honda racing employees Udo Gietl and Todd Schuster (in hat).
(2022 update: Moriwaki and Honda continue to collaborate today. Midori “Miniskirt” Moriwaki is a principle of Honda WSBK team MIE Racing.)