After using my 5' KingKutter Rotary Cutter, for the first time, I noticed a couple of issues. The U bracket that is designed to give some play in the deck over rough ground, binds and provides very little flex. Also noticed that my tractor mower combo had very little space between rear tire and cutter deck. It actually rubbed the tire one while going over a side hill. After a quick search on TBN, found a few others that had similar problems, and had worked out some improvements. Note: these are not picture of my mower or tractor.
Moving the U-Bracket to the lower bolt, and the rear mounting arms to the top, provides room for flex. Actually when I did the mod, I left the support arms on the lower bolt and straight bolt on top.
Binding can still occur on the pin when it comes in contact with the support.
Compress the U bracket in a vice, and add some thick washers to the pin side, prevents the binding.
Add a lower set of lift pins
Using a bi-metal hole saw you can drill holes in the lower support and add two new lift pins. I removed the support arms from the mower and drilled the holes while arms were in a vice. Note that the above photo lowered them to the frame and turned them inside. This was done for a sub-compact tractor, and not needed for 200 series Jinmas. I mounted mine about three inches above what is shown here. The results provided about two inches of additional tire to deck clearance and flexed more on the very uneven ground I mow.