picture would be good to get an idea what it looks like
http://support.ktm-parts.com/entries/491659-KTM-Vin-Number-Identification-ChartFrame Number Identification 1982-1989 Models
Designation 1st 4 Digits
Year
Frame Number
Year
Frame Number
1982
From 8106-8205 (total 9 digits)
1986 From 8506-8605
1983 From 8206-8305 1987 From 8606-8705
1984 From 8306-8405 1988 From 8706-8805
1985 From 8406-8505 1989 From 8806-8905
Frame Number Identification 1975-1981 Models
Frame Numbers Starting From 1st Digits (from 8 digit numbers)
5 x x x x x x x
1975 9 x x x x x x x 1979 to 90607184
6 x x x x x x x 1976 00 x x x x x x x 1980 some 1980 starting from 90607186
7 x x x x x x x 1977 01 x x x x x x x 1981 from 000820484 to 00921378
8 x x x x x x x 1978
Frame Number Identification Some 1982 Models
From 103 28000 to 104 29300 mix of 1982 250 WR
From 107 30169 to 107 30648 - 1982 250 WR
From 109 30950 to 109 30999 - 1982 400 WR
From 109 31013 to 109 31816 - 1982 125 L/C 125 WR
From 110 32000 to 110 32400 - 1982 400 WR
From 202 32479 to 204 33146 - 1982 420 WR
Engine Model Specifications
FM * X X X X X X 50 Mini Adv. / Pro Jr /Pro Sr.
X * 55 X*X X X X X X 400 cc 2 Stroke
B65*X X X X X X 65 SX X * 56 X*X X X X X X 420 cc 2 Stroke
X * 49 X*X X X X X X 80 cc X * 56 X*X X X X X X 500 cc 2 Stroke
X * 50 X*X X X X X X 125 cc X * 57 X*X X X X X X 4 Stroke Rotex
X * 52 X*X X X X X X 175 cc X * 57 X*X X X X X X 4 Stroke KTM
X * 54 X*X X X X X X 250 cc X * 858 X*X X X X X X 640 LC4
X * 55 X*X X X X X X 350 cc 2 Stroke