15 inches. Hence the 15 in the product code. If you can wait for shipping tirerack.com has some pretty good deals on wheels. Otherwise call up your local tire shop to find wheels. Some suggestions would be Pomps, Pepboys, Tires Plus etc...
Your problem is definatly somewhere electrical. I would start by having the alternator looked at. You could also have a lot of dead fuses or a bad connection between something. The only way to know with electrical stuff is to take it to a shop where they have machines to test it.
I have an 87 yamaha exciter 570 and ive been having clutch problems. The main clutch and secondary clutch have so many shims in them i was wondering what would be proper spacing for them.