Motorcycle Repair: 82 Kawa kz1000 ltd, old bikes, gas mileage

Question
you previously stated "If the bike runs well off choke (stable idle, no smoke and good gas mileage) I wouldn't worry too much." , well I do have a darker colored smoke when warming up. Should I be concerned?

Answer
If the dark smoke continues once you take it off choke I would check the spark plugs to see if one of the carbs needs idle mixture adjustment.

Smoke on startup can also be due to a little oil leaking past the valve seals. A normal thing on old bikes. If it runs well don't worry about it. It would require a top-end strip down to replace the valve seals.