[Serum]

The motormount is designed around the stock spur, since these spurs are more durable than the kyosho plastic spurs. With the new hardened pinions the steel spurs are a perfect match.

The Kyosho spurs require counter sunk screws, I assume you used these.

Obviously the kyosho spur requires more room than the stock spur; if the design was setup around the kyosho spur there would most likely be play on the center diff if the stock spur was used.

If the motormount is made the original mount is used as a template;

While some manufacturers/vehicles are using tighter tolerances and different type of spurs/diffcases I can imagine a conflict will appear when you use a different spur.

Sorry this caused you any problems; what would you like to see changed?

Bare in mind that the stock steel spur is way more durable than the kyosho spur. the stock spur would make it easier to get the gearing right.