Engine not running properly when hot on my FZS600 2000

[Slaninar]

To check the downpipes, I tend to just flick a bit of water on them, and it's pretty clear that cylinder 3 isn't getting as hot as quickly, although it certainly isn't staying completely cold.

My fazer runs sweet, both hot and cold, and after longer ride, all the cylinder exhaust pipes are at the same temp (170 +-1 C), but when started from cold, the 3rd cylinder exhaust pipe is cooler than the others and takes a bit longer to warm up. Carbs synchronized, spark plugs and contacts good - perhaps this is normal for fazers?