Jacob- I think the best people do without major changes is to adjust the engine as far left as you can on its mount plate, make sure your kit drive gears' cup shape is facing out on the rear wheel, and making sure to keep your engine drive gear and rear wheel drive gear directly in line (lot's of discussions here on how to) tighten your rear wheel in it's final position trying to eek out a milimeter or two for clearance, or put on skinnier tyres (apparently they're not as hard of a ride as I thought). It seems that your chain only slightly touching your tyre will be ok. If you can wipe your sidewall clean after a ride, and there's no loss of rubber, I wouldn't worry. Just keep it all adjusted how it works. Ride!