Yamaha AT1-MX (1969-1971) Motorcross

1969-1971 Yamaha AT1MX Specs and Photos Gallery | Old Classic 2-Stroke Dirtbike

1971 Yamaha AT1-MX Red
Picture of Yamaha AT1-MX.
Model Year: 1971. Colour: Red
Yamaha AT1-MX (1969-1971) is a motorcross version of the regular AT1 enduro/adventure bike with some changes such as weight reduction, 2-stroke 123cc engine configuration, different gear ratio, etc. to get better performance for competition.

The M or MX is stands for the Motorcross edition. The M models were very similar to the regular models but has some differences on performance enhancing features, such as weight reduction, higher compression ratio, tuned exhaust, larger carburettor with 26 mm throttle bore, tires fit, tuned gearing ratio, etc. Yamaha AT1-MX is way lighter to get a better entry level motorcross. Produced only in short periode of time, from year of 1969 to 1971.

1969-1971 Yamaha AT1-MX Specifications

Based onYamaha AT1
Frame/Engine Prefix (XXX-000101)AT1
Capacity (cc)123
Bore (mm)56
Stroke (mm)50
Compression Ratio (to 1)8.0
Bhp @ rpm18 @ 8,500
Torque (kgm) @ rpm1.57 @ 7,500
Engine CoolingAir
Oil SystemAutolube
Carburetor (mm)VM26SH
Ignition SystemMagneto
Ignition Timing (mm)2.0
Primary drive gearing3.9
Final Drive Gearing45/14 (45/15)
Box Gearing 1st3.18 (2.831)
Box Gearing 2nd2.0 (1.88)
Box Gearing 3rd1.37 (1,372)
Box Gearing 4th1.0 (1.092)
Box Gearing 5th0.8 (0.962)
Box Gearing 6th-
Fuel Capacity (liters)7
Engine Oil Capacity (liters)1.23
Gearbox Oil Capacity (Liters)0.74 (0.762)
Fork Oil Ca. (cc/leg)160 (1501)
Front Tire (stock)3.00 x 18
Rear Tire (stock)3.25 x 18
Front BrakeDrum
Rear BrakeDrum
Rear SuspensionTwin shock
Front Susp. Travel (mm)145
Rear Susp. Travel (mm)110
Rake (degrees)29.5
Trail (mm)
Width (mm)909
Ground Clearance (mm)225
Wheelbase (mm)1,285
Dry Weight (kg)91

These bikes are 6 volt, kick start motors.

Models, Colors and Vehicle Identity Number

Check VIN tables for colors for your specific year.

AT1M 1969 MX VersionPearl WhiteAT1-300101 to AT1-303790
AT1M-B 1970 MX VersionCompetition YellowAT1-310101 to AT1-312326
AT1M-C 1971 MX VersionBrilliant RedAT1-313101 to AT1-317191

Yamaha AT-1 MX Photos Gallery

Yamaha AT1MX classic motorcross
1971 Yamaha AT1-MX picture.
Vintage Motorcross collection.
Restored Yamaha AT1 MX 125 1971
Restored Yamaha AT1-MX 125 1971.
Yamaha AT1-MX 123cc 2-stroke Engine
1971 Yamaha AT1-MX 123cc 2-stroke engine photo.

Yamaha AT-1MX Parts and Accessories

You might also interested to check the price of spare parts or accessories for Yamaha AT-1MX motorbike.

  • Kensun HID Kit Computer Warning Canceller & Anti Flicker (1 Pair) - $99.99.
    #1 Customer Service & Quality, HID Xenon Anti-Flicker Warning Cancellers.
    Easy and Simple installation. Usually takes less than 20 minutes! "Plug-and-Play" in most vehicles. Some vehicles may need professional installation. The manufacturer provides free full technical support with hundreds of thousands of satisfied users. The Kensun friendly and experienced team is happy to help you with any questions or issues with the installation..
    Includes: pair of warning-cancellers. Kensun. .
  • Yamaha MX61 61-Key Keyboard Production Station - $999.99.
    Over 1,000 voices from MOTIF XS.
    128 maximum polyphony.
    Stereo Aux over 1 sounds from the MOTIF series. Yamaha. 61-Note Synth. MX61
  • Razor Mx350 Mx400 Kids Youth Training Wheels - .
    -TRAINING WHEELS ONLY/BIKE NOT INCLUDED: Fits all years Razor MX350 - 400 Electric Bikes.
    -Mounting: Lock collars prevent from "sloppy" fitting wheels, that are unstable. This is the best design in the industry..
    -Engineering: Safe, sturdy design. If we wouldn't put these wheels on our children's bikes, we wouldn't sell them to you! Our design is tried n' true! SAFETY IS OUR MAIN GOAL.. Razor.
  • Fuel Tank Valve Petcock Yamaha DT1 DT100 DT125 DT175 DT250 DT360 DT400 Yamaha AT1 AT2 AT3 CT1 CT2 CT3 DT1 DT100 DT125 DT PC20 -
  • Yamaha I-MX1 MIDI Interface Cable - $110.00.
    Connect any MIDI product to your iPad, iPhone, and iPod Touch!.
    Expands the functions of Yamaha synthesizers.
    Expands MIDI instruments with all Core MIDI compliant Apps. Yamaha. . I-MX1
  • WARN 78954 ProVantage 54" Straight Plow Blade - $257.58.
    Made from thick 12-gauge steel.
    Heavy duty ribbing.
    Center cross member for added rigidity. Warn. . 78954
  • Philips 194 Bright White Interior Vision LED light (Pack of 2) - $18.99.
    Long-lasting LEDs: 12 years lifetime.
    Vision LED interior lighting can be used for interior (dome light, trunk, glove compartment) and license plate lighting applications.
    Bright white at 6000K color. Philips. Bright White. 127996000KB2
  • YUASA YTX14-BS Maintenance Free Battery - $81.99.
    12 Volt, 12 amp-hour, 200 cold cranking amps, maintenance-free battery.
    Totally sealed and spill-proof - all acid is absorbed in special plates and absorbed glass mat separators.
    No need to ever add water. Yuasa. Black. YUAM3RH4S
  • Yamaha Service Manual for Series AT1 & CT1 (1969-1971) (INCLUDES AT1, AT1B, AT1C, AT1-M, AT1B-MX, AT1C-MX, CT1, CT1B and CT1C)
  • SYLVANIA 168/194/2825 LED Premium White Miniature Bulb, (Pack of 1) - .
    Replacement LED bulbs for map, dome, and license plate applications.
    This bulb is a direct plug and play replacement for the stock 194, 168 and 2825 incandescent bulbs in your car.
    At 6000K, this LEDriving bulb is crisp, white and adds a splash of brilliance. Sylvania. 27. 194LED.BP


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