Hey, Luckystriker, you should do your homework!
Rotax is not and never was a little known English manufacturer. Rotax is located in a small town in Upper Austria.
Cagiva also was not involved in the development of the BMW F650 engine. The Aprilia Pegaso 650 was the bike (together with the BMW F 650 Funduro) that got the original Rotax 650 as its power plant. But none of the two was really involved into the initial development of the 650 single. In the case of the Aprilia it was the original and really ingenious Rotax ConCam five valve engine whilst BMW insisted on using their own four valve head on the rump and barrel of the Rotax plant. (Probably to create a visible separation to the quite similar italian competitor). The BMW / Rotax engine was further (slightly) developed while the Funduro was in production (Drive chain sprocket instead of the lousy circlip) and got further modified for the GS / DAKAR.
The Pegaso and F 650 Funduro did not only share some of their engine components but also their production facilities as both came from the Aprilia factory in Noale / Italy. Only with the introduction of the 650GS the production of the BMW single went back to Berlin Spandau. While the Funduro was available many people in Europe joked about the tank emblem being the only thing from BMW on the whole bike. (Aprilia frame, Rotax engine, Showa suspension, Brembo brakes...)