as far as differences thru the years, the 83 had a round tubed swinger on it, the 84-85s had a sqared tube swinger. as far as other noteable differences i dont think there was much of a difference on the 83-85's besides the swingers and decals. in 86 they went to a totally different setup. were the 83-85 had the round tube frame and was a 5 speed manny tranny with kickstart, the 86 was square tube framed and had a six speed manny tranny with kickstart. totally different plastics on the 86-87 model then the 83-85 models. now a 200x will not run with an r. totally different class of bikes. the r being 2stroke, even though aircooled, was a 250 built for racing, the x a 200 4 stroke, sport trike. no maatter what mods you do you wont beat an r. maybe keep up better, but not beat it. i love the 200x's and will be getting me one here in the next week or so, have had 2 of them already. a used 84, and a new 85, my dad had an 86. my 85 would get beat by the 86 everytime, but i think it was just cuz of the extra gear. on closed courses, i'd run my dad into the ground. but i think the 85 was better looking in my own opinion.
1985 KXT 250 Tecate - kx cylinder, kx ignition, bassani headpipe, answer silencer, v-force reeds, 38mm airstyker carb, +2 franks swinger, raptor rear shock.
1996 YSF240 Blaster - maxxed out!!!
Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting "HOLY SH-T, what a ride!"