Edward - I'd be VERY leery of the advice NOT to rejet. We've got a huge chorus here advocating rejetting even if you DON'T add a slip-on. The ZR-7 is jetted VERY lean from the factory due to EPA regulations, and increasing the airflow with a race pipe and/or K&N filter will just make the condition worse. It's certainly not mandatory, but everyone who has rejetted has reported the bike running smoother and with increased power! I'd ask those guys at the dealer WHY they don't recommend rejetting, given how lean the factory settings are.Edward ZR7 said:I talked to the guys at my local Kawasaki shop and they all said go with the D&D...and they recommended NOT rejetting?! They would be glad to do it, but it really didn't need it. I'll install the pipe and go from there!