Hey i run VP U4 race gas ....... i read its very sticky but very good. i took off my air filter off today and did notice it look gummy in there but very very clean. My question is how many of you run U4 ...... also is there better fuel to run, and is it a bad to change when this bike has always had U4. any opinions are welcome! thanks guys! Bike never needs choked ever and always starts ice cold on 2-3 kick.