I just bought a 94 Vn750 and the previous owner didn't take care of it. He broke off they key in the ignition and then started using a screwdriver to start the bike. The bike also backfired quite a bit from the left exhaust. I replaced the ignition, regulator, and brought a brand new battery because he had the wrong battery in it. Now I'm running into the problem where the bike wont start unless it's jumped. The bike will run fine for a few minutes and then die. This is my first bike and I'm at a loss here. Any suggestions would be greatly appreciated.