A 5" pulley should do the job as there is sufficient wrap of the belt, so slip is not an issue.
IIRR my Qa42A on my 782 uses a pulley similar to that.
I had an issue last year with a bad gear box gear, and went to a tiller box with a different ratio.
In order to use it, I just changed the auger drive sprocket to get the correct rpm,as it is a single stage thrower.
I have since purchased a used thrower gear box from evilbay and returned to origional gearing.
I found no difference in performance with either setup.
|