2004 Vento Phantom r4i loses power above idle. Checked the plug, coil, CDI, fuel flow, timing, magneto, pulled the carb apart and made sure that everything was OK. Still no power.
I disconnect the air hose at the back of the carb, and the scooter runs great with plenty of power. I remove the air filter, no power without any filter installed. I cleaned the filter (it's almost new anyway), but still no power with the air feed connected to the back of the carb. Remove the air feed, scooter runds great. Anybody got any ideas.

In case anyone is interested. Even though the old air filter looked perfectly fine, I replaced it. The scooter runs great now. 0-50mph in no time, no hesitation. Go figure.