So I recently inspected the float bowl and cleaned the main jet of my carb (as it was running a little weak when cold and lumpy when approaching top speed).
Great success! The main jet now runs perfectly and gives full power and full throttle!
However now it won't idle at all with less than 30-40% throttle :(
Could I have messed up the idle circuit? I tried to adjust the fuel/air/idle screw in both directions but had no success :(