I have a 71 K1 with "period" mods....i.e., 4 into 1 exhaust and 860cc wiseco piston kit.
Otherwise it's bone stock/original and nice overall...with NOS original exhaust set up in a box.
Obviously, a great milestone bike. Big advantage over K0 (practically speaking) is that the K1 has
throttle bar set up instead of the K0s individual cable to each carb. Makes life easier to adjust.
Back in the sixties I was there too. Only I was in Tokyo Japan -- where I grew up 10 years and
graduated from high school. Back then Tokyo was the center of action and excitement for bikes and I rode and/or owned various bikes from Nihon -- BS50, BS90, Honda Benley 125, CB72 & 77, CL72 and 77, a Marusho Lilac 250 V twin shaftie, and Kawasaki 120 Roadrunner and some other obscure 'worker bikes'.
I remember DISTINCTLY when I first laid eyes of the "Nanahan" ("7 and a half) K0 in 69. It was owned by some Japanese guy cruising by our high school showing it off. He even let us take it
for a test drive!! And so I did. What a ride! I rode it timidly and carefully as up till then I had NEVER been on such a big, powerful bike. It was huge and intimidating. And what a great new sound and ultra smooth engine. Till then, Kawasaki's W1/2 650 twin was biggest bike you could get from a Japanese maker -- except for that "Rikyo" Harley knock-off. It dwarfed the 450 Humpback Honda. That ride only lasted 5 mins or so, but I never forgot it.
First Superbike? Well...some will say that honor also belongs to Kawasaki's H1 Mach III 500cc street missle. It actually BEAT the Honda K0 in Japan by 6 months. And pound for pound, the Mach III was much faster accelerating bike....with quicker quarter mile times. But the Honda 750 had a higher top speed and was much better suited to highway cruising and long distance runs. Back in 69 and 70, however, the only people getting the new 750s were domestic Japanese riders and GIs (from Vietnam or based out of Tokyo). Most US dealers hadn't even seen them in 69 or 70, and had a time servicing the ones the GIs brought back to the US. I ended up buying a 69 H1 'blue streak'....and still have it along with a 71 H1 'blue strober'. But I just had to get a 750 Honda and so I did....that nice 71 K1. Which is 'better'? Both are classics and fun to ride to this day....but there is no doubt the Honda 750 is a more refined, comfortable and stable machine. Frankly, I'm lucky to be alive today since the H1 Mach IIIs really WERE/ARE wild uncivilized street burners and widow makers. Definitely 'over engined'. Flexible Flyer is a well deserved name too...
