I bought a bt80 and out of the box it ran super rich. To the point that it wont get over 15 MPH even with a 36 tooth on the back. I had to jet down to a 60 and full leaned out needle just for it to get 23 MPH with the cap off it and it still 4 stroked at the top. I tried a new plug gapped at .35. I'm running a 35:1 oil ratio. Everything is stock besides the intake, its an offset intake. I'm just at a loss here and bikeberry is absolutely no help at all. I've been working on regular china girls for almost 4 years now and I've never had this kind of problem.