Update: Overheating issue solved.
Just mowed for 5 hours in heavy grass (mower was out of commission for a month so the grass got out of control)
It ran at 1/2 way on the gauge for most of the mowing but crept up just a little towards the third white tick-mark when in thick grass and clippings.
View attachment 65953
I'm not sure what fixed it as I could not do the repair one change at a time. Here is the group of changes made:
1. New head gasket
2. New water pump
3. New injector nozzles
4. New valves, valve seals, and valve job
It was expensive repair as Kubota part prices are "crazy high" here in Canada so I want to make this last. Better cooling will improve the life so 'll try relocating the battery as the next step then install an aluminum Honda Del Sol radiator.
I hope this helps others on the internet as there are so
many overheating G5200 threads with no conclusions.
Runs like a champ!