Yamaha AT1

{{Short description|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.{{cite web |title=69-71 AT1 125 Specifications |url=https://yamaha-enduros.com/index.php/125cc-specs/46-69-71-at1-125-specifications |website=Yamaha Enduros |access-date=2024-08-30}} It was part of Yamaha's early efforts to expand their motorcycle lineup and enter the growing off-road market.

=Specifications=

class="wikitable" \|+Yamaha AT1 Specifications ! Attribute !! Value
Engine	123cc, 2-stroke petrol
Bore × Stroke	56 mm × 50 mm
Top speed	60 mph (97 km/h) plus
Power	11.5 BHP at 7,500 rpm
Torque	8.5 ft-lb at 6,000 rpm
Transmission	Wet, multiple disc
Suspension	Front: Telescopic fork, Rear: Swinging arm
Brakes	Internal expansion
Wheelbase	50.6 in (1,290 mm)
Dimensions	L: 77.2 in (1,960 mm) W: 35.8 in (910 mm) H: 42.9 in (1,090 mm)
Weight	218 lb (99 kg) (dry) 234 lb (106 kg) (wet)
Fuel capacity	1.9 US gal (7.2 L; 1.6 imp gal)
Fuel consumption	141.1 mpg‑US (1.667 L/100 km; 169.5 mpg‑imp) at 25 mph

=Models and Versions=

The Yamaha AT1 was available in three different models, each corresponding to the year of production:

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.

=Technical Specifications=

class="wikitable" \|+Additional Technical Specifications ! Specification !! Value
Compression ratio	7.1:1
Lubrication System	Yamaha Autolube
Starting system	Electric for Enduro Versions and kick starter
Carburettor	VM24SH
Battery	12V 7AH{{cite web \|title=Yamaha AT1C 125 Enduro Battery Replacement (1969-1971) \|url=https://www.techbatterysolutions.com/yamaha-at1c-125-enduro-battery-replacement-1969-1971/ \|website=Tech Battery Solutions \|access-date=2024-08-30}}
Ignition system	Battery ignition

=Model History and Frame Numbers=

class="wikitable" \|+Model History and Frame Numbers ! Model !! Year !! Color !! Frame Numbers
AT1	1969	Pearl White	AT1-100101 to AT1-119829
AT1M	1969	Pearl White (MX Version)	AT1-300101 to AT1-303790
AT1B	1970	Competition Yellow	AT1-119830 to AT1-144709
AT1C	1971	Competition Yellow	AT1-144710 to AT1-170509

=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.{{cite web |title=1969 - 1971 AT1 & CT1 Fuel Tanks Same Size? |url=https://yamaha-enduros.com/index.php/forum/1968-71-badge-bikes/16132-1969-1971-at1-ct1-fuel-tanks-same-size |website=Vintage Enduro Discussions |date=2021-09-17 |access-date=2024-08-30}} Yamaha has continued to support these vintage models by producing replacement parts, such as petcocks, which fit the 1969-1971 AT1 models.{{cite web |title=Brand New Yamaha Petcocks for our bikes! |url=https://www.yamaha-enduros.com/index.php/forums/performance-improvements/164-brand-new-yamaha-petcocks-for-our-bikes |website=Yamaha Enduros |date=2014-06-06 |access-date=2024-08-30}}

References

Category:Yamaha motorcycles

Category:Off-road motorcycles

Category:Motorcycles introduced in 1969

AT1