Thanks Jack, do you by any chance know what engine the model 30 came with?
The Queen originally came with an electric motor and the parts are the same for the electric and petrol model. The only real difference was the petrol engine that I know of.
Note that I have a client that has a Queen that we service and it has been fitted with a Honda engine. He has had a few cylinder mowers in the past and he always says that the queen is the best of the three that he has. This one that he bought second hand has very little trouble with it.
