Kawasaki H1 Triple Rebuild

A labor of love, still in transition

by Mark Eddy

A 1970 Kawasaki H1 Mach III. Seems like a pretty good project cycle, right?

A 500cc, triple cylinder two stroke. It became famous not only for its power, but its poor handling and sub par brakes, too! The one I had to start with has an interesting back story, like most of these iconic machines probably do.

Believe it or not, it starts for me back in 1980 in Fairbanks, Alaska. At that time I think I was still on BMX bikes but my older brother Wayne had fallen head over heels for the Kawasaki Triples. Wayne started collecting every H1 bit that he came across, no matter the condition. Through the next ten years he amassed quite a pile of bikes and parts. He’s toted these bikes and bits around with him ever since and it just so happens one made it to my back yard for storage. There it sat for several years because it was just too ugly and too far gone to restore…

Well, last year I found myself talking to him about getting his non-running H2 down here from Alaska so I could use it to keep me busy during the slower winter months of motorcycle shop operation. As we pondered the costs of getting the H2 (this is the 750cc version of the H1) here, I started thinking (or my wife reminded me), this could be an expensive carcass that might find itself lying about alongside the other. So I went outside and uncovered the rusty bits of metal that had been propped up against the fence for two (or four…) years. I started with an inventory of usable parts and then an estimate of cost on the missing or just plain un-usable stuff. It turns out the broken-down heap that I rolled my eyes at every time I walked by had quite a lot of usable bits! A quick call to my bother in Alaska and a bunch of the missing parts (including a rare peacock grey fuel tank in surprisingly good condition) were found in his piles there and put in the post - I was off to a good start.

With a glimmer of hope and excitement about the project, I began with the motor. There really aren’t too many parts inside a two stroke, and between the two motors I found I had enough usable parts for one to start with.

While the engine parts soaked in penetrating oil and degreaser, I went through the Washington State lost/missing title process. With any project missing a current registration, it seems like a good idea to make sure one is able to lay claim to the finished project. It’s not that hard really, just a little time consuming jumping through the State’s hoops.

That taken care of, I turned my attention to the chassis.

When taking on these types of projects, there are tons of little details that must be dealt with along the way and kept in mind so that time and money aren’t wasted going in directions that won’t jive with changes that are made out of necessity rather than choice. I had been researching the pros and cons of the cycle and realized I needed to change a lot.

I decided to go with 18 inch front and rear wheels instead of the stock 19 front/18 rear combo. I knew I had to toss the entire front and rear ends as they were way too small and wobbly. Remember the famous ill-handling? That had to change if this thing was going to be fun, let alone safe. I ended up using a Hayabusa front end because the top clamp could be modified to fit standard handle bar clamps and it was gold and looked pretty cool. A bit of scrap metal and a welder and I fashioned the steering stop/steering damper mount. All the while I had been searching for rear-end options. Here I got pretty lucky, I think. I found that an old FZR rear end had everything I was looking for: a metal swing-arm that could have shock mounts welded on, it wasn’t too long and was narrow enough to fit in an old skinny frame. It also has an 18 inch rear wheel, it all worked out great. The front wheel was a little trickier because there aren’t a lot of modern 18 inch wheels, but I did find one off a Honda that could be mated with the Suzuki’s calipers.

The motorcycle's engine and drivetrain were pretty much done, so that left the tank, seat, fenders and lights. This always seems to be one of the more difficult parts of a project because it’s hard to visualize until done. This is why I am still messing with it even to this day.

When I first “finished,” I was using the stock seat and chrome fenders. It was ok but didn’t “flow” like I thought it should. The next variant I removed was the chrome fenders and gave it a scrambler type seat, I liked that but… I find myself now with some time on my hands in the slow season once again and am in the motor massaging some kinks I noticed in the transmission.

I’ve decided to make it a scrambler H1. It’s not complete in this phase of it’s transformation, so I don’t know if it’ll stay that way. I guess we’ll all just have to wait and see.

Mark Eddy is co-owner of Vallantine Motorcycle Works in Seattle. The shop specializes in service for European and Japanese brands. Fall and winter months are a great time to check in your restoration project so it's ready to go by summer. Visit them online at www.vallantinemotorworks.com