Well, according to my research, bark as only had 3 engines available over the years. The original B1000 had the 45 horse 3 cyl 2 stroke also found in wartburgs, the B1000/1 had the Volkswagen licensed 1.3L four stroke, and the Belgian imports had the 1.8L ford diesel. The 1.1l polo engine was never put in them. There were just over 175,000 B1000s built and just under 2000 B1000/1s. No numbers are available for the diesels at this time. Being that yours is a B1000, it is only logical that there has been a transplant done. It should have the 2 stroke engine. But hey, I am glad it is running and that you are happy with it.