THE HONDA SL70
HEAVY AND RELIABLE
By Matt Cuddy
In 1970 Honda wasn’t going to let Yamaha cash in on the new mini-cycle craze with their JT1MX, so Honda Motors Corp’s design facility in Torrance, California came up with the SL70, a scaled down 70cc version of the on-off road Honda SL motorcycle line .
Coincidently, the SL70 closely resembled the 1969 SL90, down to the tank/frame design and slanted cylinder configuration. In standard Honda fashion, the SL70 looked good, and seemed ready to take on the Yamaha mini-enduro in all areas.
1969 SL90. 9 horsepower and 220 lbs. The kickstand has snapped off log ago, due to excessive weight.
Unfortunately a few typical Honda design features of the time, like excessive weight and over-engineering cursed the SL70 with a dry weight of 153 lbs, versus the relatively light weight of its competitor, the Yamaha Mini-Enduro at 121 lbs, wet.
1971 SL70 Nice and heavy. 155 lbs and 6.5 horsepower.
Not to say the SL70 was a pig, as thousands of die hard Honda fans snapped up the mild little 70cc buggers for their kids, and even themselves, under the guise of a “pit bike”. And of course, all the Honda hop up aftermarket folks like Poweroll and Webco produced kits to up the SL from its anemic 6.5 horsepower to fire-breathing configurations with high lift cams, big carbs, stroked cranks, big bore kits, etc. Even a Poweroll 110cc kit was offered, that required the owner to bore the cases, stroke the crankshaft, and run a paper-thin steel cylinder liner. Such was the life of a hopped up Honda 4 stroke motosport owner, who sacrificed anvil like reliability for performance.
Seeing that the SL70 was to compete against its closest rival, the Mini-Enduro, Honda did see fit to equip the SL70 with better forks and shocks than the Yamaha, and the SL came in a full street legal configuration, unlike the Yamaha which would wait to release a lighted version of the JT2MX in 1972.
Compared to the Yamaha Mini-Enduro, the SL70 was a well constructed, solid Honda that suffered from excessive weight and higher maintenance than its two-stroke rival. As one who lived the period, and competed against the Honda, the only bad thing I can say about it was the Honda level of thrashability that allowed riders to run the poor little bike on the ragged edge of with no-maintenance, that would ultimately cause the bike to explode, and render it a useless expensive door stop. [
I know this sounds impossible, but a childhood riding buddy, Joey Gould blew up the top end on his ’71 SL70 from excessive over-revving, and was out of a ride. His brother had a derelict Honda 50 step-thru sitting in his back yard, rusting away. So in typical teenager fashion, we somehow crammed the top end off that fifty on to the 70’s cases, and produced a screamer of a motorcycle. The mechanics at Glendale Honda said it was impossible, but we did it, and it ran like a bat out of hell. If you’re out there and still alive, Joey Gould of Silverlake, you know I’m not lying.
The SL70 lived on until 1975, renamed the XL70, and was actually replaced by the XR75 in 1973, a totally different machine, with a vertical cylinder configuration, and a lighter weight of 140 lbs. 1973 was a milestone year for Honda, with the release of the CR250 and CR125 MX machines. After ’73, Honda never looked back.