Bajjaj and pulsar indian DTSi engines 180cc and 200cc are fully compatible, there chinese over bored Clones in 223cc and 248cc are fully compatible brother.
dont need to worry about YBR frame becuase the engines are vibration free just like YBR own eninge and there wieght is simlar +/- 10kg hardly which is ignorable given the power gain.
Brakes: I am using a 248cc in my Piaggio with defualt Disc in front and stock Drum on rear I never saw brakes under performing same goes with YBR setup too..
I helped a guy from Chinniot to source a 223cc chinese YBR engine for his YBR-G he reached back with extremely happy face but I lost his contact I wanted to get pictures/video from him but I lost his contact..
Ab ager kisi nay upgrade kiya enigne tu I will definatly publish it here.
hope that helps.
Regards.