This may be extremely fundamental, BUT... While riding yesterday, all of a sudden, my bike started coughing and chugging like crazy. This coughing was random, but would cause the bike to die. Long story short - I realized that the breather tube coming out of the gas cap was simply being pinched by my handlebar pad. I removed my square pad and presto, tube wasn't pinched anymore. Bike ran fine after that. Like I said, this may be awfully fundamental, but for the mechanically challenged like myself, this coughing and sputtering scared the hell out of me. Ride on!