i got my first motor kit from bike berry no complaints. i got my second from spooky tooth. both were the 66cc/80cc motors. the first was a flying horse, the second the grubee skyhawk angle fire head. the flying horse was a decent motor till i decided to go through the sandy trails behind my appt with the stock airfilter. the stock air filters suck, i urchased a lowprofile airfilter from sick bike parts, and its awesome. the grubee i put on my trike build with a shift kit, and although i havent broken the motor in yet, it runs beautifully. Basically just look through out the various vendors. Although i must say sick bike parts has great shipping and great customer servise. Spooky has good customer service average shipping times. Bike berry well i hated the wait with their shipping but that was over a year ago. havent seen their customer service, never talked to em. umm thats my pinions, but i would suggest a grubbee, i have read posts about the angle fire not being better than the stock 90 degree plug, and vice versa.