this is from Snakeibf "our European Grom member" 160cc review
Yuminashi 160cc touring kit dyno results
There is not going to be a perfect cam that works great throughout the whole rpm range, because the lobes are fixed. This is why a high lift longer duration cam works well at giving extra power where it will give good performance in a certain rpm range. I want it to make the most power where i spend most of the time in the upper rpm range. Manufacturers usually sell their bikes with fairly mild cams so they idle well and cruise nicely, but they sacrifice top end power and throttle response. The only way to have both is to have a way to vary valve timing, not just ignition timing. This requires a much more sophisticated and expensive valve train system than what is on the grom/msx. Basically you need to decide what you like best. The crower cam feels like it favors torque in the mid end of rpms. The Yuminashi pulls better from mid to top. It really is up to you which you prefer. For racing and riding twisty roads the Yuminashi may be preferable. If you like to stunt and want a bit more torque on the bottom and mid range the crower may be better for pulling wheelies.