The head on that Lifan 125 is very restricted and you won't get much airflow. Pretty much a waste of money to upgrade to a bigger carb with that head. They're not even worth porting the ports are so small in them The head on the Lifan 150 is pretty much a race head with a more aggressive cam. If you at least drop on the 150 head with a VM24 505 or VM26 606 you'll feel a nice difference in performance.
If it'll run... I'm ridin'!!!
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