Once my Sportsman Flyer build is complete...... (long pause ) I want to re-think and redo the engine mounting system used in my Huffy -Davidson (see my avatar ) rubber blocks to isolate the engine. Logically motor mounts as used in vehicles provide vibration isolation and dampen drivetrain torque relief. But empirical data from major MB builders and my own experience restoring vintage Harleys tells me that a hard mounted engine, firmly attached to the frame is if not perfect survived and were used for decades . I may have to make my own engine mount for the Huffy-Davidson as it gets reworked, I promise to give you all a comprehensive evaluation.
Forgive my digression, I have no empirical data to verify rubber mounting an engine could slow or impair motive force. Might be rough on the drivetrain as I think I am experiencing
Tom from Rubicon, WI