Mike,
There is a sensor in the photo that I put in my post. The sensor is not too expensive, so I bought one which I carry with me, but I chose not to change mine out when I did the belt. I am not convinced that a new one would last longer then the one that I currently have in there (which had been changed). I think you get a sensor that lasts or you don't and it is kind of luck of the draw which you will have on your genset. The belts and the sensors fail the most of any components that can cause an over heat shut down.
If you have the time add the wire mod to the sensor that I posted. You basically make a wire loop with a male and female spade lug so you can unhitch and measure through the sensor to ground without pulling the generator all apart. The measurement is now made from the access door. If you get the overheat fail shut down you will be able to tell if it is a bad sensor or a belt in the future.
If you knew it was the sensor that was bad you could bypass it temporarily if you had to. I gave some thought into making a sensor access plate in the top cover so I would be able to change that without the hassle but never got to that. I also thought of using some kind of push pins in place of the screws on the back of the cover but I just threw in the towel and put it back together.
I cannot think of anything that is prone to failing that you should change beyond the belt and maybe an air cleaner as a maintenance item. Antifreeze is a question, it may be time to put new in. That may be why the sensors tend to fail from deposits on them. Oil filter, oil, and fuel filter at some interval when due. Brushes seem to last a long time in these.
Later Ed
