Your machanic/dealer must have pushed it out. You have to tighten the belt after just 10 hours too because it stretches.

On my first 650 belt I got 5300kms out of, still on the second belt with 11,000kms on. I am always in high unless in a mud hole or going up steep hills. You just have to keep the clutch engaged when floating through the trails, a lot less jerky and more controllable and easier on gas. You don't have to ride in low, just keep your belt ajusted.

As far as over heating, you have to clean your rad from behind, you will be surprised how much dirt comes out from behind, also take the side panel off so you can get at it better, you have to do this after every mudding session and more, a pain but part of having a rad down low. I have never over heated my bike.

You have one of the best bikes out there, just a few tricks to keep her working good and you will be haoppy and a pig in slop.

I have only smoked my belt once and that was running in high range with the front brakes on spinning the weeds out of my driveway, I should have had it in low for that.(lol)

Don't get discouraged, she will please you yet.