John Deere 5425 Problems

Webi have a 5425 with at 542 loader. I noticed about 6 months ago that there is a valve chatter noise that comes from the left side of the engine when seated and facing. I sucked an earwig into the rigid fuel tube on a 2355n, similar symptoms. I found it when i was removing the lines to replace the fuel lift pump, which was not in. Webi have a '06 john deere 5425 that is hard to start after it sets in the barn for more than 4 or 5 days. Recently we had to split the tractor and replace the starter ring. Webjust bought a new 5425 mfwd with the power reverser. The first time i used it i just drove it ahead and back a few times and parked it in the shed. Webafter 5 years, my 5425 has lost all its power. I can pick up round bales but it will not pull my hay cutter anymore. I have been told it needs an electric fuel pump to. Webi have a 2008 5425 john deere tractor. It has 714. 5 hours on it. I replaced the inner and outer air filters 21 hours ago, fuel filter 20 hours ago, and an aftermarket speed.