Smoke from crankcase breather vent

[nezzer]

I recently got my 650 working after about 7 years off. It is up and running with a top end rebuild, pod style air filters, and a new boyer ignition system. My question is this, with the pod air filters I lost the stock air box so I installed a little air filter just for the crank case breather vent. When the bike is running, I get a small amount of smoke out the crankcase breather air filter. When I turn off the bike, I get a puff out the filter roughly equivalent to someone exhaling a drag of cigarette smoke. I don't seem to be burning through oil very quickly. I have about 100 miles on the engine after the rebuild and the oil level still looks good.

Is this normal? I am certain I would not notice the smoke if I had the stock air box. If it is not normal, what could it mean? Bad valve guide maybe?

Thanks.