QM200GY (XF200) lost 3rd gear, possible causes?

That wasnt anywhere near a perfect fit to be honest. I dont recommend this type of engine when someone wants to build something similar on a DT125R frame. It does not go in straight away and almost everything will be on its way (swing arm, downtube, the tube down under which carries the shock linkage and all the tubes under the engine). Its easier to use CB clone engines, they are so much more compact.

i would be abit worried with a CB clone engine not as well put together and the original honda CB engines are well past there sell by date. im good though getting new bike on thursday that will easily have enough power once iv run it in and deristricted the CDI and airbox

I dont have much experience with CB clones but thanks for the info.

Good info