Sounds like my fuel pump is on its way out. Loud humming and it has been hard to start. It is a Walbro and is about 6 years old. What is the latest on fuel pumps? Is the Walbro still state of the art and who is selling them and how much??? I see a fuel pump on Kirban's site listed as "high performance" for $135.00. Any thoughts and input is appreciated.