78 kz650 loosing oil from somewhere

Ive got a 78 kz650 that doesn't smoke at all, starts right up and drives fine. Im loosing oil though, and there are no unusual leaks. I say unusual because i am loosing about a quart of oil between fullups (gas) and the small amount of oil i see on the cooling fins is not a quart or even close. I can only think that the rings are pretty bad, but why doesnt it smoke then? can someone please tell me where im loosing oil, what to check/test for, i just cant tear into her till i get the head for my car back from the machine shop. thanks for any and all help.

Is there oil in your airbox or escaping from the breather tube?

It's probably just worn. If it's high mileage or not maintained they can burn a quart of oil every 150 miles and not smoke noticably. Even at 160,000 miles I was not smoking, but using a lot of oil. Showed up on the plugs and the amount of sludge in the engine.

I have pods, but no oil in them at all, as for the "its probably just worn" what do you mean? the rings? where is this stuff going? on my dirtbike when the rings get worn-out she smokes like my gramma at a funneral.