Honda probably would have built this engine this way if they could have if it wasn’t for all the emissions and “efficiency” BS. This makes this bike run like it’s supposed to. Don’t get me wrong it’s not gonna scare you, it’s still a 125….but it pulls up hills, gets up to speed quickly….it no longer falls flat on its face and you don’t have that scooter like “pin it and wait for it” scenario anymore….it just makes the bike way more fun to ride. Again…like it was meant to be. Sounds better too…way snappier. Every Grom needs this mod minimum (of course with corresponding intake and exhaust). Worth every penny