Aermacchi Harley-Davidson Baja (SR-100, MSR-100)

Years built: 1970, 1971, 1972, 1973, 1974
Bikes produced:  
Price in 1971:  
Vehicle Ident. # (VIN): 8B (MSR-100) and 6C (SR-100)
Engine: 2-Cycle, Single Cylinder, 98 Cubic Centimeters, Air Cooled
Bore and Stroke: 1.97 x 1.97
Compression Ratio: 9.5:1
Gas Capacity: 2.5 Gallons
Transmission: 5 Speed Gearbox
Carburetor: Dell'Orto MB-24A
Electrical System:  
Saddle Height: 34.05 Inches
Ground Clearance: 11.7 Inches
Wheelbase: 51.2 Inches
Weight: 212 Pounds
Wheel Rim:  
Tire Size (Front): 3.00 x 21
Tire Size (Rear): 3.50 x 18

We have to differ the Baja between the MSR-100 and the SR-100. In fact, it is the same bike but the MSR is the competition model without an electrial system like headlamp or tail light. The SR-100 is the streel legal version with a simple electrial system which also features a brake light. I am not 100% sure, but the M in MSR may stand for Motocross.
The electrical system was available seperatly from Harley-Davidson to convert your MSR-100 to a SR-100. Factory MSR-100 do have a VIN starting with "8B" and Factory SR-100 have VIN starting with "6C". Sometimes you will see the VINs mixed up, but this is probably because people dismounted the electrical system from their SR-100 or bought the electrial system later for their MSR-100.
If you stand in front of a Baja you will be amazed about the great ground clearance and the large cylinder and head which looks like it is a 250cc engine.
The Baja was not available in Europe, but instead a complete different motorcycle with the same idea of a small motocross racer called the RC-125 which had a similar engine with 125cc instead of 100c like in the Baja.

  • Pictures No. 01 and No. 02 show a 1971 MSR-100 (competition model)
  • Pictures No. 03, No. 04 and No. 05 show a 1971 SR-100 (street version)
  • Pictures No. 07 to No. 11 show a 1974 SR-100
  • Picture No. 12 shows the cover of the 1971 owners manual
  • Picture No. 13 shows a restored 1972 Baja
  • Picture No. 14 shows the Baja Toys which were available from Polistil

SR-100, 197101 SR-100, 197102 Baja SR-100, 197103 Baja SR-100, 197104
Baja 197105 Baja06 197407 Baja 197408
197409 1974, Baja10 Baja11 Owners Manual12
1972 Baja13 Baja Toys, Polistil    

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