Ok I'm new on here so of there is already a thread about this please just point me that way.
I have a 2011 ninja 205r. I am getting a Yoshimura Slip on TRC exhaust next month. Do you think I should rejet? If so what size should I use? The bike is stock other then body work.

 

I am not really sure, but at what altitude are you tuning for? I have had to tune all of my stuff to even run the stock exhausts let alone an aftermarket one.

Welcome to KF

 

I'm in Cali it's practically sea level. The exhaust says you don't need to rejet but I want the best proformance.

 

Try out the manufacturers recommendations of course. And if you start overheating, backfiring, bad dips in mid throttle response or a too sudden hit in the top end. You will need some fine tuning to get the best throttle response and control. Each ride is different so recommendations are only a ball park toss and maybe not a home run.

 

Ok thank you. I'll just ride it for a week and see how it runs. I e-mailed the company and ask what size jetting they recommend. So I will see. Thanks for your input.