MY WR400 has been runninig great. Rode it Last Sunday, no issues. Went to start it WED, got it running for a few seconds... then it just quit... no stumble, still had the choke on, turned it off... gooses the throttle QUIT WOULD NOT restart!!! tried for about 20 minute to restart... NOTHING. tried again Thursday.. nothing. Tried today... NOTHING Fuel.. check removed the spark plug and grounded to frame NO SPARK.... I mean ZERO...NADA. replaced plug... still NOTHING checked fuses and connections... all look good. WHY would I SUDDENLY lose my spark without warning? Thanks in advance!!