Complete moped newbie here, stuck with a 50cc moped that really doesn't want to do faster than 15MPH even on a straight road. In particular it's a Jinlun 50 (great make yeah I know) and it's brand new. Seeing as I know almost nothing practical about the design of these things, I've no idea where to start looking. What should I check out? Maybe it's just an extreme case of not being worn in correctly, but I'm having trouble imagining that it would create a uniform drop in power to 15MPH on a flat. Going up a hill isn't even worth talking about.
It's worth noting it's still restricted. As the moped didn't even come up listed in this site's moped profiles, here's a link to a site selling parts for it: