White smoke and jerk at cold start UNO 1.0

Hi, I just bought a uno for 400 euros 2 years tüv etc.. little macking no rust thought all wonder bar but when I started the next morning engine he jumped quite hard and smoked about 30 sec. pretty white (vapored) whether steam or smoke was I can say net but I tend to nem mix from both smell pretty much like unburnt gasoline. well, when it’s warm it goes great too. he only turns on when the motor is cold ́, can you tell me a n what it could be so candles should all work because if it’s warm it runs round and good so I’m stunned oil or water should he burn net too because later there’s nothing more. could that be on the ignition system.?? as much as I’ve seen is the valve lid seal leaking oil comes out but it wouldn’t have to lie down there has nothing to do with the cylinder or anything like that .. hmmm. am curious about your opinion thanks..