The 83-85 200x's are very different machines from the later 86-87 200x's,they hardly have any interchangeable parts. You need to weigh out the advantages and disadvantages of them. 1st gen 200x parts are plentiful and cheap, 2nd gen are a bit harder to come by. 1st gen had kick starter issues. 2nd gen had a 6 speed, 1st gen 5 speed. As for reliability, pre-rebuild to my 200x it smoked like a train and had little compression. Started first or second kick always. I went out there today to get it ready to ride in -15 and started first kick. Maybe im just lucky, or these things are bullet proof. It also beat a raptor 350.
1984 200x
1985 "auto x" 200x. Had a rough life
1982 atc200
1983 atc200e
198? atc?? w/ first gen 250r front end
1982 atc185s