I have never turned mine off. I usually ride in the UP and the temp has very seldom gone above 30* F while I've been riding, has ran fine and gotten great fuel milage compared to the others I ride with. I was riding with a friend last year, he has a 2001 SRX, he had never turned his on until we started riding on a very cold morning (around -5*F) and his machine started back firing and missing. We stoped to check it out and it seemed like he was fouling plugs, we installed 3 new ones and all seemed fine for about 3 miles then it stared it again. This time when we lifted his hood I noticed that the coolant was turned off to his carbs. When I asked him about this he had told me he had never turned them on since he had the sled, didn't even know that the sled had carb heaters on it (claims he rode it in this cold of temps before with no problems with the heaters turned off??). I explained that the manual says, turn on if colder than 32*F, so he did. Had to use a pair of pliers to turn it on. Installed 3 new plugs and all has been fine since. -Ed