G'day,
once again i totally agree with grumpy that playing with pulley sizes can spell trouble especial if you are towing things around with it. the simple facts are that ride on mowers are geared to mow lawn and maybe pull a small load as present. when you start altering the sizes and effectively putting more load on the gear train things start to snap, grind and burn. i had a friend who set up a normal ride on with a 6" front pulley instead of a 4' and literally got from his drive way to the road before he grated the crown gear in the box, probably due to his handy clutch work.
but the point is that and mower of this vintage has seen allot of lawns, and probably already has a dicey gear box as it is so playing around with it isn't going to contribute to its longevity, and as grumpy says you will no longer be able to achieve low speeds for towing ect.
regards jay
