If people think of the 1972 Imola 200 in Italy, they think of Ducati taking a place in the first rank of motorcycle producers with Paul Smart's win on Dr. Fabio Taglioni's bevel-drive 750cc V-twin. A lesser drama that weekend was the collapse of the press tent, blown down by a police helicopter's low flyover.

In the race, an intense but smaller drama began as an Italian Kawasaki team prepared to refuel its 500cc H1R. The bike swept into pit lane and stopped. A designated mechanic stepped forward to remove the fuel cap as a second man advanced with the fuel. Just a moment, there’s some problem with the cap. The mechanic tried again, this time wrapping a rag around the shiny but edge-knurled cap for better grip. Nothing.

Serious time was ticking away. The man carrying the fuel had set down his burden and now furiously shooed the first man—obviously, a weakling—away. He gripped the cap expectantly and…nothing. His hands slipped ineffectually as the veins in his forehead and neck became prominent.

The rider, seeing any chance of a decent finish disappearing, waved them both away with thunderous body language. Idiots! Cretins! The mechanics wilted in the glow of his rage. Now the rider grasped the cap with his leather gloves. This will succeed! He gripped. He twisted. Prolonged strain and…nothing!

The rider threw his arms into the air and stalked off, flinging his helmet, leaping the pit counter, and disappearing.

Was it a change in fuel? European nations that year adopted a 5 percent maximum for benzene in gasoline. Was it toluene, substituted for benzene, that had caused the fuel cap’s black elastomer sealing washer to swell, making cap removal impossible? Was it a new two-stroke mystery oil? A dibasic acid ester, perhaps? A polyglycol? Or just the existential finger of fate?

The mechanic tried again, this time wrapping a rag around the shiny but knurled-edged cap for better grip. Nothing.

Later that year, I saw updated fuel caps on factory-backed Kawasakis. Welded around the outside of the cap was a sheet metal ring in the form of coarse gear teeth.