Alright. I have a used bike which ran well untill I installed a spark arestor into the exaust. Just curious....It will idol smoothly with the joke on. If I push the choke in the engine dies. If I try to give it throttle with the choke on while it has a smooth idle, the engine backfires. I'm thinking the carb needs to be tuned....not really sure what is going on. Anyone with any thoughts or ideas please let me know.