Hi, I have a redmax 7001 about a year and a half old, used a lot during last fall and spring cleanups. I've maintained it, but now it's starting to get a rattling sound in the engine, but doesn't seem to have lost too much power. I've changed the plug, checked the carbon, cleaned fuel filter and changed air filter. Does this sound like the beginning of the end of this blower and if so would it be worth fixing? could there be some adjustment?