Yamaha DT50M
 A Yamaha DT50 | |
| Manufacturer | Yamaha |
|---|---|
| Production | 1978 – 1981 |
| Successor | DT50MX |
| Class | Motorcycle |
| Engine | 49 cc (3.0 cu in) 2-stroke Torque Induction single |
| Transmission | 5-speed manual, Multi-plate Wet, gear |
| Suspension |
Front: Telescopic forks Rear; Twin shock swingarm |
| Brakes |
Front: Drum Rear: Drum |
| Wheelbase | 1,210 mm (48 in) |
| Dimensions |
L: 1,860 mm (73 in) W: 805 mm (31.7 in) H: 1,045 mm (41.1 in) |
| Seat height | 780 mm (31 in) |
| Weight |
72 kg (159 lb) (dry) |
| Fuel capacity | 4.7 l (1.2 US gal) |
| Oil capacity | 1.2 l (0.32 US gal) |
The Yamaha DT50M was the entry level 50cc in the Yamaha DT series. Production started 1978 and ended 1981.
It was a dual purpose street/trail bike aimed at the 16 years age group of moped riders taking their first steps into motorcycling.
From 1978 onwards, all new mopeds were restricted to 30 mph in the UK. The selling point of the DT50M was style and off-road riding as opposed to out-right speed of the FS1E of previous years.
The DT50M had a 'sister' bike in the form of the TY50M which was designed as a Trial-bike/moped. It shared many aspects including the 50 cc engine. The TY50 however had been manufactured before 1978 and early models were unrestricted (30 mph) but had pedals which qualified them as a moped pre 1978. However, although unrestricted it's safe to say, they were not built for speed with torquie engines and high gearing.
The DT50M was fitted with twin rear shocks and 19"/17" front and rear wheels, this is in contrast to the later model DT50MX, which had larger 21"/18" wheels and a monoshock rear suspension.
The DT50M had a road bike sister called the RD50M (sharing the same engine unit), and similarly the later DT50MX had a road bike sister called the RD50MX.
Engine and transmission
| Engine type | Air cooled, single cylinder, 2-stroke |
| Bore & Stroke | 40.0 x 39.7mm |
| Compression ratio | 5.7:1 |
| Induction | Piston port and reed valve |
| Lubrication System | Autolube |
| Starting system | Kick starter |
| Clutch | Wet, multiplate |
| Gearbox | 5-speed, constant mesh |
| Carburettor | Mikuni VM16SH |
| Battery | 6V 4AH |
| Charging system | Flywheel magneto |
| Ignition type | Magneto |
Identification (uk)
| Model | Frame/Engine number | Production code | Model year |
| DT50M | 2M9-000101 on | 2M9 | 1978 |
| DT50M | 2M9-100101 on | 2M9 | 1979 |
| DT50M | 2M9-200101 on | 2M9 | 1980 |
The Model year is not necessarily the same as the year of sale or first registration.