Text from Yamaha Circuit Magazine, from 1977, Issue 4, detailing the 1978 Yamaha range:
YAMAHA TY250, TY125 & TY50
For 1978, Yamaha have a three-machine trials range headed up by the well- proven TY250, the machine developed by Mick Andrews, double European Trials Champion, and used by hirn to win such classics as the Scottish Six Days Trial.
The TY250 lines up alongside another popular Yamaha trialler, the TY125 that combines performance with lightweight for those trials riders who prefer to utilise a favourable power to weight ratio rather than outright horsepower.
Finally, there's the little TY50M ... a little jewel of a trials bike in miniature with a 3.2bhp 50cc engine featuring reed valve Torque Induction, Autolube oiling and a four-speed gearbox.
The Yamaha TY50M might be a lightweight in terms of engine size, overall dimensions and horsepower but it’s very definitely in the "heavyweight“ class when measured in terms of its "go-anywhere" capabilities.
The little TY50M is a genuine trials machine, capable of tackling many of the same sections as its bigger brothers in the Yamaha trials range. Just like the rest of these machines, the TY50M draws on the experience of double European Trials Champion, Mick Andrews, and this experience is reflected in the machine's styling and specification. It's no “boulevard" bike posing as a trials machine ... the TY50M, while quite happy cruising the cafes, is quite capable of dealing with the rough stuff.
For off-road enjoyment, trail riding, novice-class trials or even as a snappy little street bike, the TY50M brings the real excitement of a genuine competition machine to motorcycling's smallest category.