Atco Balmoral 17se

Hi
I have an Atco Balmoral 17s. The drive shaft had come adrift and caused a bit of minor damage which I have managed to sort out, my problem now is that the engine runs uncontrollably fast or cuts out if I reduce the throttle.

I have stripped and cleaned the carburettor, fitted new gaskets, float and valve.

I now think that it is a problem with the governor mechanism. I removed the arm and if I rock the spindle it fastens to it feels to be catching inside the block. I'm a bit wary of what I should do next.

I would appreciate any advice members could give me as to what I should try.

Many thanks,
Lance