I have had a few lifan motors and I thrash them straight out of the box. I flush the ****** oil out first with cheap mineral oil. There is no need to spend alot of $$$ on oil for chinga engines, because its cheap u can afford to change it more regularly and completly flush out old oil. I still have 2yo chinga bikes that have been thrashed from day 1 and they still run very well and dont miss a beat.
So in my opinion with chingas- once there warm there run in