wellllllllllll..for one, the 1985 trx250 fourtrax never came with a gear layout of R-N-SL-1-2-3-4 !. as far as I remember ?, they were R-N-1-2-3-4-5, all of these models ( year/model ) were , have a 5 speed transmission , they did not have a layout like your saying. only honda atvs that I know of that have that tranny is some of the trx300's, and the early trx350's ( 1986-1989 us models ) ( 90-92 Canada models ). not aware of any trx250 fourtrax's having that transmission.