Adventure Bike produced by Yamaha motor company
Yamaha AT1
The Yamaha AT1 is a single cylinder enduro motorcycle produced by Yamaha Motor Company from 1969 to 1971.[1] It was part of Yamaha's early efforts to expand their motorcycle lineup and enter the growing off-road market.
Specifications
Yamaha AT1 Specifications
| Attribute |
Value
|
| Engine |
123cc, 2-stroke petrol[1]
|
| Bore × Stroke |
56 mm × 50 mm[1]
|
| Top speed |
60 mph (97 km/h) plus[1]
|
| Power |
11.5 BHP at 7,500 rpm[1]
|
| Torque |
8.5 ft-lb at 6,000 rpm[1]
|
| Transmission |
Wet, multiple disc[1]
|
| Suspension |
Front: Telescopic fork, Rear: Swinging arm[1]
|
| Brakes |
Internal expansion[1]
|
| Wheelbase |
50.6 in (1,290 mm)[1]
|
| Dimensions |
L: 77.2 in (1,960 mm)
W: 35.8 in (910 mm)
H: 42.9 in (1,090 mm)[1]
|
| Weight |
218 lb (99 kg) (dry)
234 lb (106 kg) (wet)[1]
|
| Fuel capacity |
1.9 US gal (7.2 L; 1.6 imp gal)[1]
|
| Fuel consumption |
141.1 mpg‑US (1.667 L/100 km; 169.5 mpg‑imp) at 25 mph[1]
|
Models and Versions
The Yamaha AT1 was available in three different models, each corresponding to the year of production:[1]
- 1969 Yamaha AT1
- 1970 Yamaha AT1B
- 1971 Yamaha AT1C
Each year, the AT1 was also available in the Motocross edition designated by an M. The M models were very similar to the regular models other than a few performance-enhancing features, such as weight reduction, higher compression ratio, tuned exhaust, larger carburettor with 26 mm throttle bore, and tuned gearing ratio.[1]
Technical Specifications
Additional Technical Specifications
| Specification |
Value
|
| Compression ratio |
7.1:1[1]
|
| Lubrication System |
Yamaha Autolube[1]
|
| Starting system |
Electric for Enduro Versions and kick starter[1]
|
| Carburettor |
VM24SH[1]
|
| Battery |
12V 7AH[2]
|
| Ignition system |
Battery ignition[1]
|
Model History and Frame Numbers
Model History and Frame Numbers
| Model |
Year |
Color |
Frame Numbers
|
| AT1 |
1969 |
Pearl White |
AT1-100101 to AT1-119829[1]
|
| AT1M |
1969 |
Pearl White (MX Version) |
AT1-300101 to AT1-303790[1]
|
| AT1B |
1970 |
Competition Yellow |
AT1-119830 to AT1-144709[1]
|
| AT1C |
1971 |
Competition Yellow |
AT1-144710 to AT1-170509[1]
|
Parts and Maintenance
Some parts, such as fuel tanks, were interchangeable between the AT1 and other Yamaha models of the same era, like the CT1.[3] Yamaha has continued to support these vintage models by producing replacement parts, such as petcocks, which fit the 1969-1971 AT1 models.[4]
References
