I have had a repeating problem this summer with the "flapper valve" sticking in the engine of my SRM 2110 Grass Trimmer. As a result no gasoline flows into the clear bulb and the engine won't start. Suggestions welcome. I don't know where the flapper valve is or how to access it. The repair guy keeps saying that is the problem. As I have to drive 30 miles round trip to get to the repair shop I would rather know how to fix it myself. Thanks, Josh Lichterman, Grass Valley, CA