I assume you mean that it smokes when first started and then it eventually stops smoking. Some of that is not uncommon, although you need to explain more of the details before we can advise if yours is abnormal.
1. How long (time/miles) have you owned the bike.
2. How do you know it is using oil and how much is it using, including how do you check the oil level.
3. Does it smoke every time you start the bike, or only some times.
4. How have your ridden the bike and how did you park it right before episodes of smoking.
5. How long does it take to stop smoking.
The more info the better.
2001 Z3 3.0i Roadster
(Topaz Blue, 5-speed manual, Sport Package, CD radio, heated seats and mirrors, non-power top via special order)
"Beemer" is for my BMW motorcycles!