some specs to determine which model you have are; 1983 black frame 1984 blue frame ,1983 cushion rocker pivot bolt is 15mm dia 1984 17mm dia ,1983 had yellow painted front forks 1984 had no paint but yellow plastic protectors ,you would need to show a picture of the disc brake front end to determine what it is off as 1983 & 1984 had drum brakes only the 1985 model had disc and they are rare as,if the front end is Suzuki and the rim is gold anodised its off a 1985 rm .the rear shock remote resovior on a 1983 model has a flat screw adjuster on the end next to the hose 1984 had a black plastic knob adjuster on it,the dates of manufacter are stamped on the rims 9/82 will be the start of 1983 model and 9/83 will be the start of 1984 models and rear rim on both models should be stamped 2.50 for the width size ,250cc models had 2.15.and the rear axle on a 1983 model should be 17mm dia and 1984 is 19mm dia hope this info helps you sought it out as you don't know if motor is original as the both look identical oh and the 1983 swingarm is a hollow rectangular tube section the entire length and the 1984 model has a solid plate section where the axle goes through, but best way is to put up some pics cheers Barry