If your engine kit came with a 410, can u use a 415 instead? If so...then u could use a hub adapter.
Seeing that MM's 2 dealers piston bikes and bikeberry don't sell what you
need you can order directly from MM and get a hub adapter with a
sprocket that is made narrower to fit 410 chain and other undersized
415 chain that comes with the kits.
I think that you would be better off upgrading your 410 chain to 415 or
even better to 41 chain. and getting the adapter and sprocket from bikeberry.
Even though the chain that comes with some of the kits is called 415
it is not to ANSI standards and is less than 3/16" between the plates.
Some of the Chinese kit chains are some weird size between a 410 and
a 415.
410 is 1/8" and 415 is 3/6" between the side plates.