Meet the 120

This is the best bike in the world. I don't care what you say, or what you have, this is better.

It's a 1967 Kawasaki 120 Road Runner. Originally, it started life as a bit of a turd, being designed as an enduo with a goofy speedometer, goofy headlight, goofy luggage rack on the fender, bizarre 2 x 4 speed transmission, no expansion chamber, and practically no suspension front or back. This one, however, has been modified.

Let's go front-to-back. The crappy forks have been replaced by a new set from a Suzuki about a decade newer, complete with about twice the travel, and leading-axle. All the street-legal stuff has been removed for a bare, aggressive-looking bike. The stock chrome pipe was traded for a hot expansion chamber with no silencer whatsoever, which not only made the bike loud, but gave it unbelievable power and torque, with instant response from the 1/8-turn throttle. The old shocks which looked like mozzarella string cheese were replaced by high-end Girlings and forward-mounted for more travel and better action.

This is the only bike I've ever ridden, aside from a 490 Maico, that can raise the front wheel on-command in either first or second, regardless of where the rider has his weight. It isn't very big on horsepower, but its torque is legendary. Once it was drag-raced against a Hodaka Ace 100, and the race was surprisingly a tie. Then the two were taken to a motocross track, and whenever there was the slightest incline, the 120 would absolutely disappear into the distance.

[MrJohn]

I had the 67 120 Roadrunner back in 1967 as well. Didn't perform any mods on it but I loved that bike! Wish I had one now. Later I got the Kawa 175 Bushwhacker. A good bike also but somehow I had more fun on the 120.

[JETZcorp]

The expansion chamber is something we happened upon by chance. My dad was buying some part for... one of his Maicos probably, and we happened to notice the guy had a 120 in his garage as well with this old aftermarket pipe people used to have made in the '60s and '70s. He was going for more of a restoration so we traded straight-across.

I think that's the only thing done to the engine, honestly, aside from opening up the filter a bit (as shown). The pipe seriously transformed the bike 100%

[cachorro]

I had one of these.. Bought it brand new in 68., had the high/low 4 speed. paid about 400.00 for it. was a lot of fun in the woods. was a bit of a turd though. Later in life, I met Mr. Kawasaki and family in Japan and actually went with his daughter, Michi. It all ended badly but some pretty good memories.

[robmallory]

So what kind of expansion chamber did you find to put onto this bike. I'm working on a c2ss, which is the street version right now. Also have you shaved the rotary valve at all. Just looking for some ways to get it as hopped up as yours obviously is.

[JETZcorpMotors]

@kriegdouch We don't have many pictures of what it was like back then, but if you look in my favorites you'll see there's a video of a 120 C2SS that kind of gives you the idea. Ours was similar to that, but being a different model it didn't have all the street stuff, and it was quite rusty. I can remember sand-papering the rust off the wheels myself when I was 11, and not being too excited about "upgrading" to a bike 10 years older than the one I had then. Man, was I ever wrong!

[JETZcorpMotors]

@bdk565 Well, the 120 has the advantage of being a rotary-valve two-stroke. That's a pretty powerful combination, especially with a proper pipe on it. But still, I do have to be careful with it. Not only do the rear shocks get their asses kicked over big bumps, but the forks are only really held on in one place, which gives the front end potential to just go completely; a potentially fatal disaster. The bike is simply not built to withstand the performance it is now capable of.