The purpose of an aftermarket exhaust system is to increase airflow by reducing the restriction in the oem exhaust. If more air flows through the bike without a corresponding increase in fuel flow then not only has the aftermarket exhaust served no purpose, but the bike could easily lose power and run hotter than before. The less restrictive the exhaust, the more likely this is.mjm174 said:Is there a aftermarket pipe you can get that does not require rejetting or adjusting the carb?