Hezemans engines (a company of former European Touring Car Championship winner Toine Hezemans) used to import Rotax engines in The Netherlands throughout the 1980's and 1990's. Not just an importer, Hezemans were deeply involved in development of the Rotax 100cc kart engines. According to some, they were the main contributors to the rise to competitiveness of the Austrian brand against the Italian manufacturers. Apart from reselling Rotax engines, Hezemans were known for their own Rotax based engines as well. Oftentimes these were experimental prototypes, where a Rotax engine would provide the base components, while some parts would be replaced with Hezemans designed ones. Therefore most Rotax 100cc parts and Hezemans parts are interchangeable. Stories are known of experimentation with water cooling before Rotax themselves were building water cooled kart engines. Hezemans had a cylinder barrel and head cast with its own logo, which was mounted on the crankcase of an air cooled Rotax engine.
Somewhere in the mid-1990's Rotax started its focus on the Rotax FR125 Max TaG engine and Rotax and Hezemans parted ways. The entire Hezemans stock of engines and parts was acquired by Kart-Parts in Heijen (http://www.kart-parts.eu/), which is now the most likely place to find parts for Hezemans engines and most Rotax 100cc engines.