In spring of 1971 Englishman Cliff Carr arrived to ride my Kawasaki H1-R. At Daytona Kawasaki were offering an “A-kit” to update 1970 engines to ’71 spec. This included cylinders, heads, carbs, pipes and an advance-retard CDI that worked in a fascinating way. All this for $550.

The ignition worked well through Daytona (our chain came off) and into subsequent races. Then it became flaky—sometimes it was hard to start the engine. At the same time we were seeing as many as five member of the official team, trying to push-start one of their bikes. There was popping but no solid, satisfying immediate fire-up. This became a kind of paddock joke. At the end of the year I visited Steve Whitelock, who was Yvon DuHamel’s mechanic.

“I’ll show you something,” he said, pulling a cardboard box out from under his bench in the team shop. It was filled with ignition stators that had become flaky.

When Cliff made a trip home, he returned with a German-made Kroeber CDI. It had fixed timing and low 10 millijoule spark energy, but it started and ran the engine. We began to do well in Canada and in Kawasaki contingency points for non-national races (automotive ignitions at that time provided ~ 60 millijoules per spark).

But there was trouble. One hot day in mid-summer we were waiting, listening for him to come around. When he did, we heard a single pop as he rushed past. Next lap it was two pops.

We did what we could on the spot—filling our cooler with motel ice and packing an ice-filled towel around the Kroeber’s stator until moments before it was time to run. It got us through the weekend, but not the next one.

You can’t charge a capacitor with AC pulses, which is what the three-pole Kroeber stator generated. There had to be rectifier diodes to turn AC into DC. Those diodes were potted into the stator’s dark blue potting epoxy. They were getting so hot that their peak inverse voltage tolerance was degrading. When the engine would misfire, its unburned charge went into the exhaust pipe, waiting for the next firing of that cylinder to ignite it. Pop.

I made a new mounting plate for the stator out of insulating phenolic plastic. I raised the ignition cover away from the crankcase on spacers. I drilled large holes in the cover to allow plenty of air circulation.

Pop-pop. We weren’t having good luck with CDIs. Should we return to the original contact-breaker ignition?

Then we heard that Kroeber had fixed the problem by relocating the diodes into the three little rubber-mounted ignition boxes that we had mounted on the front fairing stay. When the new unit arrived, performance was good. Cliff won the Kawasaki contingency, lapped Mosport (near Toronto, Ontario) under Hailwood’s record, and even managed to beat Yvon once. 26 meetings, as the English say.