IM doing the same thing with my 98 YZ400. Im told you need to change the flywheel and stator (aftermarket or stock WR flywheel and stator). Im looking for a WR parting out but so is everone else. Parts are hard to find, I did almost get the stator from electrix but after calling them they told me I also need the flywheel... Loooking at about 6-700 dollars for the change from MX to dual sport (fenders, brake switches, headlight, battery, stator, flywheeel, engine cover) it is worth it though... to be able to ride 24hrs a day! Im told any WR stator and flywheel from 98-2003 will work and bolt right on.