Many years ago, when Byron Originals was still in business, orange case Sachs engines were used..They were, and still are, VERY good engines...Byron changed from the factory Sachs engines to A&M engines with machined cases and bad cranks, then to the Byron Mustang 50cc engines...Iron Bay must have found a stash of orange case Sachs engines, the company was bought by Makita a few years ago and now the engines are blue..
The orange case Sachs engines were, and are, the best...