1995 arctic cat zrt 600 triple melted lines

i had just bought this sled from a friend and this is my first sled and the lines around the carbs are all melted and the tank line is a little melted along with the tach wires any suggestions with what caused it or what i should check out to fix it or what would have caused it i would really appreciate it thanks

1995 arctic cat zrt 600 triple melted lines