Identification numbers for the 1970-1978 ATC90 [aka US90 '70-'73]

89cc, OHC Single, 4-Speed Auto Trans, Dual Range SubTransmission

FRAME VIN NUMBERS

1970-1971.....US90-100122 and up......Offered in 4 colors....AquariusBlue,BrightRed,SummerYellow, and ParrotGreen
Balloon tires with molded in wheels, Front fender is steel, Rear fenders are fiberglass,No headlight,Swivel lock handlebars, folding footpegs.

1972-1973.....US90-200001 and up.....Offered in 2 colors....TahitianRed and MightyGreen. Has a headlight with black shell.

1974.....ATC90-1300001 and up.....Offered in DaytonaOrange only....Headlight shell matches the body in color....Stationary mount handlebars.....Front fender is now plastic....Rear fender is still fiberglass...Staionary mount footpegs.

1975.....ATC90-1400001 and up....Offered in LightScarletRed only...Rear fender now goes to plastic.....Finally gets steel wheels.

1976.....ATC90-1500001 and up....Offered in LightScarletRed only...Decal changes only

1977.....ATC90-1600001 and up....Offered in LightScarletRed only...Decal changes only

1978.....ATC90-1700001 and up....Offered in LightScarletRed only...Decal changes only

ENGINE NUMBERS

1970-1971.....US90E-100122 and up
1972-1973.....US90E-200001 and up
1974..............ATC90E-1300001 and up
1975..............ATC90E-1400001 and up
1976..............ATC90E-1500001 and up
1977..............ATC90E-1600001 and up
1978..............ATC90E-1700001 and up

For those wondering why the 1970-1971 and 1972-1973 models are listed in pairs......The reason is Honda didn't officially have "year models" until 1974 on any of their off road vehicles.

There is no differences between a 1970 and 1971 and there are no differences between a 1972 and 1973