[sanddrag]

There was no coupler included in the kit for the Jideco motor. This is part of the challenge. The plastic coupler included is for the Nippon Denso motor. Some teams have been able to find gears that sort of mesh with the Jideco (not perfectly but it works). Some teams make something that has a bore of the OD of the gear teeth, and then put set screws into the "valleys" of the teeth. Another option would be to do this but try filling the bore with JB weld (or similar compound) before placng it over the gear. Some teams go all out and carefully measure the gear and CNC their own coupler. This is probably the best route, but not all teams have that capability.