those 02 mods had that cooling issue. the fix is your snow flap. get a 03 or newer and it shouldn't do that so much. either that it could be your coolant temp sensor. when the sensor fails, it misreads the temp and the engine 'protects' itself from further harm. that happened to my 8 last year, and replaced the sensor. didn't over heat, only in marginal conditions.
2003 Edge-X 800
Vforce 3 reeds, Powermadd Boost bottle, updated c.d.i. slp powder pro's, 1.25 predator track, fox racing clicker rear, rydefx center and skis, 1 in handle bar riser, specialty x can. 11.5 in cobra yellow tint windshield, and a sportech yellow tint lightshield.