changed header caskets and now no power running terrible srted cheers

[darrsi]

The Fazer is fairly insensitive to the type of silencer fitted. Unless a mouse has built a nest in the exhaust I doubt the change is the cause of the problem.
What was the weather like when you tested it? The cold, misty mornings we’ve had lately are ideal for carb icing. If the heater passageways through the carbs have become blocked that can give symptoms similar to those you describe.

Does that heater circuit actually do anything?
My pipes were all cleaned out, but if i don't put Isopropyl Alcohol in my fuel over winter it instantly gets carb icing.
Been proven year after year so i know exactly how the bike functions without it....shite basically.
Mechanic confirmed it as well, and said that chemical treatment would stop it happening.