If your motorcycle doesn't perform properly, the problem can be traced to the air intake system. In particular, the throttle body may be to blame, as this crucial assembly is responsible for letting the needed amount of air into the engine. Older motorcycles have a relatively simple construction with a steel cable making the choke open once the rider turns the throttle, while more modern bikes feature a throttle-by-wire system in which a computer controls the choke, but over time, any of these mechanisms may need some attention and repair.