The writing "Does anyone know boygofast's website?I can only find them on ebay,when I go to boygofast,com and I click on engine kits it shows bikeberry,gasbike.net etc....All the engines I have found for boygofast on ebay says they have no warranty once mounted on bike...." has me wondering. If the warranty is no good after the engine has been mounted, then what little speck of good is their "warranty" at all? How many purchasers test their engine before it is mounted into their bike frame? Let me know!
Many dealers receive a box with an engine from China and send the unopened box with engine out after getting your money. They have not a bit of a clue as to whether the engine is new or salvaged from a reject pile and cobbled together. The don't check for head stud torque, nor for an unseized gear train, or anything else.
I have noted that BoyGoFast and Kings both have given recent purchasers a bad time when the purchasers question the quality of their engines. Neither asked the purchaser to return the engines for inspection. Purchasers were simply denied warranty service.
Look for a business web site and endorsements from other purchasers. Stay with dealers who maintain untarnished reputations. Going with the cheapest purchase is not always smart.
MikeJ