Motorcycles cannot fill up at the pump or bowser.  They must park in a special zone away from the pumps, and anything.  You guess how much fuel you can fit and then carry the petrol in a can or kettle to the motorbike.  Sometimes the attendant will carry and pour it, sometimes you must do it yourself.  Some petrol stations even have some sort of cage system for the motorcycle but we never saw that.

Sometimes the reality was a little more flexible than above.  Some stations would allow the use of the pumps directly.  But even then, with many you could not run the engine near the pump, you would need to push the bike to approach and leave the pump.  Or you would need to park the bike outside the white line marking for the pump area and stretch the hose across to the bike.  Often they would move a couple of fire extinguishers in place, just in case.

Most of the time we would try to get fuel in small groups to reduce the concern.

As we left Tibet and travelled through north western China the rules got even more strict.  Movement in the region is much more restricted.  It is an area of China I gather few foreigners pass through.  We would be stopped by at least two police checkpoints per day (same for locals), our guide also had to register us with the police in each town we stayed at.  Our movements around the town were monitored and we were told to stay in the vicinity of the hotel.  In some areas we were just not allowed to leave the highway.  Although a few of us did when we were running out of fuel one time.

In north western China, petrol stations were like high security zones.  There were high fences and boom gates with security staff to control the entry and exit of all people.  Locals would have to scan their ID and faces. On many occasions we were prevented from entering petrol stations because we did not have a Chinese ID Card.  Sometimes we would eventually be able to enter using our passport and temporary Chinese Drivers License.