I have a 1992 300ex. It is mostly stock. After riding at the river for less that an hour, I stopped to check the oil. The oil plug/guage was so hot that it burned my fingers. Is it supposed to be that hot? I have a 250R that doesn't seem to get that hot when riding all day.

 

The oil is what helps keep the engine cooled along with lubing the engine, so you would expect the oil to get hot.
That would be kind of like putting your hand on the radiator of your car after driving.

 

I can see your point. Is there a cooler availiable? I have heard of tapping into the oil line that goes to the head and installing a cooler but I would think that this would not let enough oil up to lube the cam. Any ideas?