Years produced: 1965-1969
Total production: N/A
Claimed power: 29hp @ 7,000rpm
Top speed: 98mph
Engine type: 305cc two-stroke, air-cooled parallel twin
Weight (wet): 156kg (343lb)
Price then: $699
Price now: $2,400-$4,000
Most bike nuts who grew up in the Sixties are fans of British, Italian or American classic motorcycles. Not Greg Davis, who ended up restoring a 1965 Yamaha YM-1.
“I was always interested in bikes, but wasn’t allowed one in high school,” he says. “I preferred the look of the Japanese bikes. They seemed to be designed all in one. They were just more aesthetically pleasing.”
In school, many of Greg’s buddies rode Yamahas, including many two-stroke twins, so he got an opportunity to become familiar with models from these years, even though he wasn’t allowed to ride one at the time. And after leaving school, Greg finally did get to own a YM-1, a brand-new 1965 model that he kept for two years. It made a lasting impression: So much so that, in spite of all the bikes he’s owned since, it was a YM-1 that Greg wanted to restore.
Read about Greg Davis' review of owning and riding a Yamaha YM-1
About a decade ago, Greg began scouting around for suitable candidates and also started picking up leftover YM and YDS parts that were being cleared out by local Yamaha dealers. In most jurisdictions, motorcycle dealers are only required to keep parts for models less than seven years old, and Greg’s shrewdness paid off in the number of original parts he amassed.
Finally, he placed an ad in a local “buy and sell” free newspaper, and discovered a rather sad looking YM-1 in a nearby suburb. After some negotiation and horse-trading, Greg acquired the 1965 YM-1 in exchange for engine work he did on the previous owner’s 125cc BSA Bantam D1.
“It was said at the time that you couldn’t build an air-cooled two-stroke twin bigger than 250cc because it would overheat,” says Greg, reflecting on the fact that the YM-1 was Yamaha’s first attempt at a bike bigger than 250cc. “So Yamaha built the Yamaha YM1 to prove a point.”
Stickler for detail
Once he had the bike, the next step was the restoration. However, Greg didn’t just restore his Yamaha YM-1: he effectively remanufactured it. How else could you describe the process of resurrecting a 40-year-old Japanese motorcycle using nothing but 100 percent authentic Yamaha parts? That’s right. Every item on the YM-1 was either supplied with the bike or came from the factory. No pattern parts were used anywhere.
“I tried to get everything as authentic as possible,” says Greg. “Some parts could have been substituted, and no one would have known. But I would.”
Take the footpeg rubbers, for example. The 1966 items had ribs running all the way round, while the 1965 did not. Greg scoured swap meets and contacted other members of the Vintage Japanese Motorcycle Club to find these and other similarly obscure items, though a correct front fender eluded him. “I was told they were unobtainable,” he says.
The original fender had rusted right through, so Greg built up the metal with braze before sending it out for plating. But he was never completely happy with the results. Since then three original fenders have turned up, so he’s been able to fit the correct item.
Each part was a project in itself. For the seat, Greg refused to substitute an aftermarket cover. He started with an original Yamaha seat, removed and unstitched the cover, re-dyed the cover material to its original color, then had the cover re-stitched.
The paintwork turned out to be a special challenge. In order to find out how the red finish was obtained, Greg rubbed down some of the existing paint to reveal the separate layers. The original red was a kind of candy apple, which Greg has reproduced using the same number and thickness of layers as the original.
The white was even more problematic. Greg eventually determined that it was a flat white with a pearl lacquer coat. The original lacquer had discolored, but fortunately that shouldn’t happen with modern lacquers. To get the correct swoop of the two tank colors, Greg painted and stripped the tank twice before he was happy with the result.
As a machinist, the engine work presented no problem for Greg, so he saved it for last. The restoration took a total of three years, but the result bears witness to Greg’s fastidiousness. At first glance — and even under more detailed inspection — the YM-1 has none of the mirror polishing, excessive chrome and heavy powder-coat painting that mar many over-restored bikes. Instead, it looks just like it would have when it left the factory. As such, it’s an almost perfectly authentic example of one of the machines that so dramatically turned the traditional motorcycle industry inside out in the 1960s.
Greg’s next project? He has a lead on a rare 1962 250cc YD-3 … MC
• Vintage Japanese Motorcycle Club
Read more about this motorcycle:
• History of the Yamaha YM-1
• Greg Davis' Yamaha YM-1