Puff of Smoke at Start-up?

[irq3]

This is a general question about propane generators. Is it normal for a propane generator to have a puff of smoke come out the exhaust when starting? It seems to do this only when the engine is cold (when it has not been running for a week or so). I am wondering if it is related to the combustion process?

[pcfrisch]

It due to a little moisture in the intake and or a little oil on the cylinder walls.