I need help bad. I recently took my bike to the dealer with a bad gasoline issue. They drained the tank and cleaned the jets. When I picked it up it started and idled great but ever since I got it back the engine stalls periodically when the clutch is engaged. The engine does not sputter it just stops. The dealer thought it was an electrical issue so they replaced the ignition sensor. I still have the problem. Because I never had a problem until the bad gas issue I feel this is still a fuel system issue and not an electrical problem. There is no pattern to when this occurs except that it happens after the bike warms up (five to ten minutes of riding). My bike is in very good condition with low mileage. I also had the air box removed and added a custom exhaust system. Any suggestions as to what is causing this would be most appreciated.