Good looking bike, man! I'm digging the green. Somebody has shown this bike some love.
Aftermarket pipes are gonna discolor. But, since the bike is new to you, best to check out the carbs anyway. Look through the FILEBASE up in the right hand corner of this site and you will find good info on reading your plugs, setting up your carbs, etc. The popping when cold could be a lean condition. Does the engine consume oil?
