Hi, New to the board guys? hopefully this will be a quick and easy question. I am helping a friend change out his spark plugs in the morning, he fowled his out after changing out an exhaust.

Question is do I replace by removing the tank and airbox to get access to them like the yamahas or drop the radiator and go that way like the 600rr. I have a shop manual for the 03 600rr and can print out that info but need to know about the 1000.

He added a slip on jardine can and it elimated the exhaust value, is that normal? I have swapped out several full systems and they always fowled the plugs, so thats what I told him. if thats not it, it would be the rect. reg.
Thanks in advance guys.