I have 1 bike 1 trike I do not know what engine designation applies in the states,Here in Aus. we have off the shelf,KIT, F80 A80 R80 The only diff I can see now is between A80 and R80 one engine is 6:1 A80 other 9:1 R80 The kit comes from China and the luck of the draw is if it all works ... Both engines I purchased in kit form did not start from new.... First engine had casting minor fault magneto side ,NO SPARK.. slight grinding to align magneto yoke to crankshaft and GOOD to go... 2nd engine flower nut not on right at clutch side once again minor rectification... I ride both machines 8Klm to s/market and back constantly. No problems... Bike with R80off the shelf 9:1 comp. Great ride and will give more frights than are good for you,Trike with A80 small rear wheels ,and its all about gearing will climb a wall,I push the pedal once on this thing and that is it it will go forever uphill and down dale, and I live in the country with some pretty mean hills.My story to the new, would be Buy a mid range priced kit,fit it get it to work and see if you like it... Your prices in the states are almost identical to ours,Kit $165- $185 Try it on a cheap Walmart/Big W /KMart I used Grand kid leftovers,after that If that is your bent move into modifications. China make these things for a market of a Billion people,sure there not all going to be perfect,cop it that is mass production and for what you pay for what you get its a damn good deal.. I read on this forum and other places about made in China, What you pay for is what you get,as an old Tradesman ,most Makita tools in Aus come from China,Most DeWallt also some many others to numerous to mention.Most Outboard Motors under 9Hp have all been made in China even for the US market for 10 years, All that changes is the decal on the cover... Give an Ebay Kit a Go if you happy take it further with the great help you will get from the people on this forum.. OH and bye the bye ,have been to USofA West coast only and a big thank you to the people who all made us feel so welcome. China 1 Billion,USA when I was there 390million Australia 24million and a land mass almost up there with America, We have to travell a long way to everything.. As an aside my first car was a 1936 5 window coupe,Ford of course, no three windows or anything really cool ever made it here,Channeled over the chassis, Original flathead valley cover drilled out risers out of 1"tube and triple Stromberg 97's NO ELDELBROOK or any off the shelf gear...I digress try the bike have fun ask the members I have not had as much fun since the early days,and I love to see some of those unmade gravel roads zipping by under me wondering what the hell if something malfunctions Sure as **** you will know your alive!!!!!!!