MM sprocket adapters are available at Pirate Cycles now. This would be the super easy way , you can simply add washers to make it perfect. Gotta spend 50+ bucks though. Worthy investment in my book if your going to be in motorized bicycle for awhile.
Manic Mechanic (New Arrival)
You can always try and flip the sprocket too and see if it clears everything. It will clear the tire that way for sure but it might hit your brake arm/frame or put your chain out of alignment.