got a buddy with a ds 650 . bike will pop and backfire with air lid on . if wee remove lid it runs a lot beder.he is running stock

 

??????
what i missed something.

 

Too rich, lean it out and leave the lid on, follow oldmanracings reccommendations in the thread stock carb mods

lean it out means jet down, move the needle clip up towards the top to lean out 1/8-3/4 throttle, put smaller main in for 3/4-WOT, and the pilot circuit, screw air fuel mixture screw in till it stumbles, then back out till it stumbles again, and set screw in the middle ofthe two. if you have to screw the screw in more than 1.5 turns, put smaller pilot in. I have had a long day, so I may be wrong, if I am someone will chime in, and correct me. Hope this helps