Hi Max,
I finally got to alter the castor wheel on the back of the mower yesterday, I had originally had welded it about centre of the back of the deck, so this time I welded it in line with the centre of the motor and that improved things so it is now mowing as it should. The only downside is the ATV is a bit bulky and its turning circle isn't good. Now all we have to do is wait for the Spring rains to come and see how it handles the really wet ground. The way the weather is looking though we may not have a rain problem this year, probably end up mowing dust