for the most of the parts ?, yes..they will swap out. BUT !!, some parts are different through the years. the front brake drums on 1986 will not work on any other model cept a 1986 !!. then they changed the left engine side cover, it has a breather tube on some models, others don't have this in the later years. the breather system changes, keep an eye on this !!. if my memory serves me right ?, the front pinion gear on the 1986 is different, from 1987 to 1989, they all are the same, but the 1986 is all on its own..lol. plastics from a 1986 ( front fender and grill ) are only for the orange sub-lights, they will not work for a fender that has clear sub-lights, the grill is different, as well as the whole front fender for the grill. racks, bumpers, all will swap,bolt on. rear fenders from the 1986 from the factory, as well as the front fenders, did not, do not come with holes for the racks ?, you have to cut them out for the racks to bolt up through them. the 1986 uses the battery to fire spark plug, where is, 1987 to 1989 all use the stator to fire spark plug. these are a few things that come to mind ?!..lol. can't remember if the ignition switch is different or not ?, ( wire wise ) .Yes I read that somewhere on here that in Canada they made them until 1992 or 1993 but the 87-88 parts will fit ??
all of the old school trx350's use an electric fuel pump to pump gas to the carb, the fuel tank is under the seat, lower than the carb . they have a fuel pump, and a fuel cut-off relay . if you just want to test fire the motor to see it if it will turn over ?, shoot some starting fluid to the back of the carb or air filter, then kick start it over, if the compression is great ?, it will fire over after a few kicks over .Apparently the one I have has an electric fuel pump and will not start with out the battery? I'm really looking forward to getting this bike! Lol