The RP you checked at my office was a 200cc Variant by lifan (Yamaha OEM), this is a 250cc more powerful variant by Zongshen (Honda OEM) .
The owner of this bike has his own vision and he will be updating the bike to a complete sports style bike with Daul Disc brakes, alloy wheels, fat tires, mono shock e.t.c.. My job was to assist him putting a fat motor inside it with countering all known issues one can face during motor swapping.
No, it was done on request by the owner of the bike.
Jis bhai ko engine liga ker diya hai is GS150 men usnay GS 13k ka liya tha scrap halat men with docuemnts.
You are welcome I just shared the details of labour and other charges in a post you can check.. There is a complex series of engines comming out of china its hard to balantly recomend any single engine... most of the time it depends what is available and best option. good names are lifan, dongben,zongshen, loncin.
@omer.s @homayoon thank you, I am glad you liked it... frankly the bike is in ugly shape but the owner has some really cool plans to shape it hardcore sports bike. I handed over the bike to him and I have no details what is the progress so far ... may be one day I spot it on road.