I bought my first kit and was very excited at how smoothly it went together and how well it worked. I started reading these forums and found that one guy said "replace the plug wire and boot and the plug. The ones that come with the kit are junk". Another said " replace the chain the one that come with the kit is junk" another said replace the chain guard another said that the tensinor was no good. The rag sprocket would fail the gas filter and hose was junk and on and on. Lol So far I replaced the plug wire and boot and plug, the master link broke on the chain ( bought a #41 from princess auto but it is also from china, will it be any better?) I bought a new gas filter and line today my chain guard failed ( at least I now know what that noise was). I bought a kit to replace all the studs and nuts and bolts as suggested. Is there any reason to suspect that the engine is any better than all this other stuff. I love my bike AND thankfully I love to tinker.