I have a friend who bought an 07 ZX6R can you do the KLEEN mod on these? I know it doesn't add much. So i was just wondering

Also, I've done the KLEEN mod on my 03 ZX6r and the exhaust gas smells really different now. is that normal?

 

Got nothing to do with the Mod. What do you mean "smells different"? Just bad gas most likely.

 

Well it just smells really strongly of gas where as before i couldn't smell any exhaust really at all before. I fill up like every other day.Maybe i need to run some FI cleaner through it or some octane booster.