T6061 aluminum collar and plate adapters fit over the existing Yamaha YG4i Apex or YG4 RX1 crankcase cover and provide secure, aligned & pinned attachment points for all types of gearboxes, including the most popular Mohawk AK7, as well as Rotax C, Hirth, Simonini, Arrow, etc.  In use since 2012.

YG4 Gearbox Adapters

YG4 RX1 Adapter
YG4i APEX Adapter
YG3 Nytro Adapter
  • Please contact MAC to provide your PTO shaft cover after you place your adapter order, so that the cover and adapter can be aligned and pinned as a set.  If you have not yet purchased an engine, contact MAC to arrange for a core charge credit.