If the Goped runs wih a Zen G230RC, then it is identical to the engines used in the FG Sportsline onroad cars, and only a tad less powerfull than the G260RC.
It will ned a new carb link.(Or new carb with FG style link)
New/Modified Clutch housing, if it is to run on an Off-Road FG(Maybe also on an onroad, but not sure), and maybe new clutch.

If it is a Zen 23LH, then read Above...