i have. they need to be adapted in many ways. they are also very very finicky. if you can get it running right though im sure they are fantastic. Naz in seattle has gotten a couple to work. but honestly with the materials to adapt and the ammount of time spent you really should buy a HPI, PVL, or Power Dynamo cdi kit. that is untill someone comes up with machined parts to adapt that xr50 setup.