Transit time in PEK for a connecting flight to CTU then onto KTM

I am flying SMF/KTM in January. My routing is SMF/LAX/PEK/CTU/KTM. I have a 1 hour 30 minute connection between my CA984 flight arrival into PEK and my CA4194 departure flight to CTU then onto KTM. Is the 1 hour 30 minutes an adequate transit time between those two specific connections(PEK/CTU) as it show as "questionable" on my itinerary?