Why's my exhaust header pipe glowing?

Q. I have an N-reg Kawasaki GPz500 which is restricted at the moment. I noticed that as it was warming up the other night, the right hand exhaust header pipe was glowing red but the left side wasn’t.

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Does this mean that the left cylinder is not running well or the right cylinder is running too hot and would the restrictor kit have anything to do with it?
Sticky 100, MCN Technical forum

A. If it’s glowing as you describe that indicates an excessively weak mixture into the ‘glowing’ right cylinder.

You need to get it into a dealer to be checked out before it burns the valve heads or does other damage through being out of balance.