I have a 2001 ES 450. It only has 400 miles on it. I ran it all fall deer hunting without any problems. Once about 2 months ago the oil overheat light came on while out on a ride around the lake. It happened in front of my house at the end of my ride, so I didn't pay much attention to it. It happened again last Sunday numerous times while pulling my 2 small kids on a sled (I have used the atv about 5 times since the first time it happened, but for very short distances puilling an ice fishing sled). I had only gone about 6 blocks when it first came on. I'd let it cool for a few minutes (temp was 25 degrees), start it back up, and it would come on again after about 200 yards. After going through this about 3 times, I rode home (about 6 blocks) without it coming on. I checked the radiator last night and it seems clean. I can see through it. I have an extended warranty until this summer, but would like to know if there are any obvious answers. I called the dealership and they basically provided no suggestions. I'm sure they'll have an impossible time reproducing it, so I'm not really excited about driving an hour and dropping it off for some indeterminate amount of time. Help. If there's anything that concerns me it's oil problems.