THE JT1 MINI ENDURO
By Rick Sieman
THE ULTIMATE VINTAGE MINI BIKE
1971 YAMAHA JT1 MINI ENDURO
BY RICK SIEMAN
Some of our readers have reminded us that they didn't grow up on Huskies, Bultacos and Maicos. Nope, many of them grew up on the bike you see here, the Yamaha JT1 Mini Enduro.
Hundreds of thousands of these little bikes were sold in the early 1970s and many riders learned all of their skills on these great minis. What you see here is a JT1 that has been restored to the 10th degree by Rob Phillips at http://www.huskyrestoration.com.
Rob recently did a Steve McQueen Husky resto on our site and it was well received by the readers. So we figured we'd give these guys who were on the little bikes a real treat. Take a peek at this JT1 and let your mind wander back 40 years or so.
This bike came with or without lights. So the aficionados out there can compare the following numbers to see exactly what they have.
JT1 SERIAL # JT1-000101 - 041708
JT1 SERIAL # JT1L-200101 - 201152 W/LIGHTS
JT2 COMPETITION SERIAL # JT1-050101 - 071150
JT2 SERIAL # JT1-300101 - 330000 W/LIGHTS
They came in the following colors:
1971 Yamaha JT1-L Desert Orange #07
1972 Yamaha JT2-MX Yellow / Black #04,
1972 Yamaha JT2-L Mandarin / Yellow
By Matt Cuddy
In 1971 Yamaha had the bright idea to produce a 1/2 scale version of it's popular enduro line, so youngsters could get away from their evil handling mini-bikes, and ride a bike just like dad did. The motorcycle was called the "Mini-Enduro" and within a couple years, it started a whole new craze, known as the "mini-cycle".
The 1971 JT1MX was a mild 60cc rotary valve little beastie with a four speed box, autolube, primary start, and approved USFS spark arrestor. To keep costs down, Yamaha cut corners on the suspension, and designed the front forks with one spring in the right fork leg, using compression damping, with no spring on the left side, with rebound damping. The rear shocks used rebound damping, which was just fine for a beginner.
But just like its larger brethren, the Mini-Enduro stayed in stock form for about 20 minutes after it got home, and put under Dad's wrench. What began as a mild starter bike for the pre-teen crowd, soon became a fire-breathing rocket for a new venue at MX tracks, mini-cycle racing.
Big carbs, cut rotary valves, high-compression sunburst heads, expansion chambers and radical port jobs were offered by all the popular hop-up/pipe makers of the time, and could be purchased and clamped on the Mini Enduro, to give it competitive power in a growing mini-cycle MX class. Some of the biggest names in MX started on the Mini Enduro, David Bailey, and Jeff Ward just a few (who later had to use an XR75 due to contract issues with Honda).
But being this was 1971, while the motor got massaged into a power-house, the suspension was neglected to the point of making the Mini Enduro an evil handling beast, even more so than its larger siblings.
In 1973 the JT1MX was replaced with the 80cc version, with better suspension, a reed valve and 20cc more displacement. And it gained about 30 pounds in the process.
But for a while, the original '71 JT1MX Mini-Enduro was every 11 year olds dream, and the bike to beat. And yes, I had one with a cut rotary valve, Bob Bailey down pipe, and a sunburst head.
They are collector’s bikes now, and grace many hallways as a coat-rack, or a vintage pit bike.