Last week, I tried to start my generator after five years in the garage. I did the basic stuff like new spark plug and fresh gas, but it kept cutting out. When I looked at the fuel lines, they were cracked inside even though they seemed okay outside. Putting in new lines made it run fine. I don't get why they go bad when not even touched. Does this happen a lot with engines that sit? What makes fuel lines fall apart over time? Let me know if you have seen this before.