Hi, Wayne and the usual suspects are:
1. Wheels and or tires worn or damaged.
2. Engine/transmission/vehicle not aligned properly.
3. Primary chain is badly worn or links too tight as a result of insufficient lubrication or misalignment.
4. Engine to transmission mounting bolts loose.
5. Upper engine mounting bracket loose.
6. Ignition timing incorrect due to a poorly tuned engine.
7. Internal engine problem flywheels have shifted.
8. Broken frame.
9. Stabilizer links worn or loose.
10. Rubber mounts loose or worn.
11. Rear fork pivot shaft nuts loose.
12. Front engine mounting bolts loose.
13. Worn out or broken universal joint on shaft drive models.
For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
The Honda PCX Honda Forza Forums
vibration when accelerating from dead stop
Honda PCX150i Owner Manual