Q. When should we change the chain kit for Benelli 600i? If we change the stock exhaust to ixil does it effect mileage - TNT 600 i?

Chain kit is not needed to change often, as it is durable part of bike. unless you use it rough or got bruised due to rust or fall.- ixil is an awesome exhaust, i have anniversary edition of it, few things can be noticed once you install exhaust- BHP will increase a bit- sounds awesome, ear orgasm- you will make bike light weight a bit that will increase efficiency, hence mileage may increase a big, but on thing if you dream of big bike mileage is not the first factor.

Us mileage should be affected I think 4 kilometre at least drop in per litre

I’ve completed 12000 plus kms on my bike and the chain and sprockets are fine. About the exhaust, I changed it after the run in (1000kms)