My 4240 Kubota is overheating. Has water, oil, and starts easy. Runs great, yet after 10-20 minutes it slowley over heats up to 6 (75%) marks on the temperature gauge. It will continue heating if I let it run - (one time at this according to the dash gage). At this time I shut it off. I Give it a break and restart. It has cooled a little and I generally put it away. No water or oil leakage or steam is visible It is a 2008 4240 with only w/173 hours on the dash. It has a front end loader and 60" mower hanging on the back. What could cause it to over heat? Could I have a cab put on it? Help this ol guy. Bad@Boy