Fellas running 363/ 370cc motors with unbalanced cranks, what's the vibration like? I can't remember back to the last 350 I had and am considering doing a 363 Sphynx for the spare duner over the winter. I probably wouldn't care for myself but usually have a gal riding that bike so vibration becomes a bit more of a concern. Probably won't go that route if I need to spend the extra coin to balance since that motor size is already getting big enough for the spare.