I just received my bike so not too many miles on it. Out of the box it would not idle, (none of them do do they?), but I adjusted the idle air mixture screw and idle adjustment screw and it now is idling high 1700rpm (not the 1200rpms they say). After that it went easily 35mph level surface I expect to go better once broke in. There is a snafu with the oil release valve underneath the seat. I called WhizzerUSA they know about the problem and they are sending me out a new type that alleviates the problem of oil spewing out the filter end onto your rear fender. For FREE. So ask them for it before you order it. The bike itself I love it. Looks good and for the most part it is a comfortable ride. Use the 40w oil got mine at O'Reillys and don't wait the 50 miles to change it do it in 10 miles..it will be black. So change it. I want to keep mine as stock as possible so I am not going to be changing the head etc to make it go faster. Quenton on this thread is the man for that stuff, you can also remove the baffle in muffler (gets loud) carefull not to pull out the insulation and you can change the plug the hotter NGK plug (I didn't) maybe this would help speed. This is a CVT clutch you don't peal out but it gets to speed just fine. Are you in a hilly area? I am in flat Iowa. Overall I like the bike. Getting any of these type of bikes mean your going to get your hands dirty, they are on hands bikes, but they are fun and simple to work on...just keep them free of dirt on the pulleys and belts and change the plugs and oil is all you need to do if you want to keep it stock...have fun!