grizzly has been sitting for years. repaired carb and some other minor stuff. Now after riding for a bit the oil temp light comes on.  It has oil in it, but can't figure out why light comes on.  After it sits for awhile light goes off again, why is it getting hot!!
help please!!!!  

I have a 2000 Grizzly 600 with the fan wired to be on all the time when the key is on. I cleaned all the fins on the oil cooler just after I had it serviced by a Yamaha dealer. I took it 5 miles down the road and the oil temp light came on. They said they flushed the system, I wonder if they blocked the cooler in doing so. I have call into them, but I am sure "it wont be their fault". I'll post again when I hear more.