not starting back up

started my ped earlier and i noticed it wasnt runnin right so i adjusted the mixture screw on the carb then the ped cut out and wil not start back up even wen adjusting the mixture screw back to its original place. any ideas why?? cheers

 

same happened to my speedy turned out the sparky had gone ?

 

cheers m8, its still sparking but ill try a new plug

 

m8 u was rite sparky had gone. didnt think it had cos it still seemed 2 spark fine