79 xs400 starter trouble

ive recently purchased a 1979 xs400 that had been sitting 5 years. i cleaned out the carbs and flushed the brake system and got her running smoothly again using the kickstarter only do to a missing start button. it started up the first couple of kicks and i'd been driving it round my yard until i could get my endorsement. i then recently replaced the button and started it several times electrically. but then it made a loud click and a sound much like a handful of quarters in a tiny little dryer. i diagnosed the problem as being the starter gear being worn down. when i went to start the bike again with the kickstart, and it also wouldnt turn the motor over. ive never worked on any type of motor really and am wondering if the kickstart assembly is bad also or if the starter gear is affecting the contact made by the kick. also i am trying to find out if the starter gear kit for the 650's on MIKE XS will work for my SOHC twin? thanks for any help