i heard glowing red header pipes are from a rich condition. so that could explain why your headers glow red with the choke on.

 

Your fan issue may just be the sending unit has gone bad. If i was you i would check the fan to see if it works. If it does then it's the sending unit. If not then it's the fan.
First:
On the left side of the quad under the tank and tie strapped to the frame is where the connector plug is that comes from your fan. Disconnect it there and connect temporary wires to it. Run Those wires back to your battery. If it runs...thats good you saved 75 bucks. If not your out..I think it was 15 for the tempature sending unit. Don't remember for sure how much that one was. I need a new one too. But any way.....[img]i/expressions/face-icon-small-wink.gif[/img]
Next:
If the fan ran like i said it's the sending unit. That is located next to the t-stat. This is on the right side of the motor and is where the upper radiator hose connects to the motor. As you are looking at the t-stat housing there are 2 sensors. The one on the left side with the 2 wires conneted to it is the one you need to replace. The one on top is the one for the Idiot light (The red light on the dash that works as an oil light and tempature light).
If your fan is bad the cheapest place i've found is offroadwarehouse.com Just call them and tell them you need the fan for the ds 650 and they'll know exactly what ya need...unfortunatly the earier ds's have fan issues. [img]i/expressions/face-icon-small-sad.gif[/img] They also go through a lot of temperature sending units.
I installed a toggle switch on the dash so i can manually turn my fan on.
Good luck

Oh BTW sounds like midLfinger called that one. Prolly was just the choke being on that caused the glowing pipes. If you only ran it for one minute that is. Thats not long and certainly not long enough to get the bike up to operating temps.