what would cause a 150cc scooter to lose power?
NO it would not.
No
You may need rotors
A defective catalytic converter can do that.
change the fuel filter
a vac leak
the shaft inside the tranny is broke.
if you have a carborator, it may have to be adjusted
If the car has high miles, try checking the catalytic converter. If it is clogged it will cause the vehicle to lose power.
Sounds like a fuel pump.
Vapor lock!