I have a 03 300ex I just had a full pipe K&N and jet kit put on my bike. It backfires alot the dealer says it will do that when you put those mods on it. I dont believe it thats why im asking. Some people say it could be an exaust leek or pilot jet. When the dealer put the jet kit in do they change the pilot jet? does the jet kit come with one?please help?

 

usually after doin that it has to be jetted to correct that, check and make sure the dealer jetted it. sometimes they tell they did but dont actually do it so ur bike can mess up and u have to take it to get fixed.