Hi all,

I have been wondering with all the stuff I read on re-jetting the bike and why you need to do it.

Currently I have K&N air filter and a leo vince SBK slip-on. to be honest, I fail to understand why you would need to rejet the bike if you install a different exhaust. For e new air filter I can understand. The restrictiveness of the air filter well influence the pressure inside the throat of the carburetor and thus it's tendency to suck some fuel in through the jets.

How does this work for a new exhaust? A better exhaust will improve the gas exchange of the engine (volume-metric efficiency). The engine will suck in a bit more air but the carburetor should adjust automatically, since that is what it does. It should regulated the fuel intake as a function of airflow. So, why does everybody say you need to rejet if you install a new exhaust?

 

You don't need to rejet if you're just putting on a slip-on. If you install a new full exhaust system including headers, then you need to rejet. The carburetors do compensate, but not enough to account for that type of change. The paper filters that Honda installs in the bikes are plenty efficient enough given the design of the engine. Adding a higher flowing filter like a K&N doesn't do anything for you if you don't replace your exhaust system too.

 

i had a slip-on and drop in k&n ran fine without rejetting and a few bike shops told me not to even bother with doing so