I have my Yamaha FZ S Fi v2.0 purchased in April 2017, now after 45000 km, white smoke is coming from silencer everyday when engine start, so service centre is saying to change the bore piston as it is blocked, I want to know the approximate cost for that and will that really affect the mileage always or any pro blem please reply.

That's a common problem when you don't change the engine oil on regular basis. The engine oil becomes too thick which causes bore and piston to worn off. I had faced same issue in my Honda Stunner at 50k km. The service centre quoted around 14000. I still ran my bike for another 15k km with oil changing at only 1500kms. Then I did the work through a local mechanic whom do I service regularly. He charged around 8000 for the same. Do not run the bike in this condition as it result in drop in mileage and power, and the piston rings will worn out to a bad condition. Get a quote from Good mechanic from your area and get the job done soon. If you are from Bengaluru I can share the details of the garage where I got it fixed.

In order to the exact price, we'd suggest you get in touch with the authorized service centers as they can let you know the exact prices. You can click on the following link to see the details of the nearest service centre and selecting your city accordingly - Service centre

One mechanic has told me 5k for piston change my bike has same problm but smoke is coming when very light when i rev it hard so does it make effect on engine