Originally Posted by
downunder
That's written by Hobbico, not by the OS factory. I suspect when it was written all current OS 2 strokes had a one piece crankcase which obviously means you can't rotate the non existent front housing
. The early Max-H 60/80 with the rear drum valve had an extra drive slot marked R for reverse rotation and machined 90 degrees from the normal slot.
Downunder is correct. The quote cited was from the O.S. FAQ page we created and maintain. It has mostly general questions, but when talking about specific products wanted, it does refer to current-production items.
O.S. used to make reverse crankshafts and camshafts for their engines. They no longer have enough demand to support production.
Older O.S. two-stroke engines that had the separate front housing could be reversed by rotating the front housing so that the carburetor was on the same side as the exhaust port, or 1/4-turn clockwise when viewed from the cockpit. All four-stroke engines need a special
reverse camshaft.
Also, as downunder pointed out, some of the rear-intake engines that used a disk for the intake valve were made to allow the engine to operate in either direction, depending upon how it was installed. The engine rotation was easily changed by the modeler.