No tip over switch cause its carb'd but this pink wire seems promising

 

fiddy, my f2 has a similar problem after a lowside from the previous owner. sold it to me because he couldn't get it running right.

it was a combination of ****ty stuff in the bowls clogging jets, and a kink in the fuel line under the tank.

 

If you removed your gauges it will cause that EXACT problem, I speak from experiance. Theres a sensor in the speedo that tells the air bypass to open or close around 12mph. Ground out that pink wire and youll be groovin.