I have a genuine XR50 for one boy and now a chinese 50cc quad. I may try to install the 88cc bore kit I have that is made for the XR50. The castings all look identical from XR to Chinese. If no one has done it then I guess I will report on my findings after I do it myself in about 2 weeks. Supposed to take the XR50 from 2.5hp to at least 4hp. You can get a cam and carb and hit 6hp. Just the bore is going in the quad though.

Anyone try this yet themselves?