rx1mtn, last spring the Yamaha northwest reps, were at the dealer when I was picking up my sled after they replaced the float bowls and they were taking to sleds out to specifictly test for overheating and what they found out was we have about 7 minutes of engine run time before the temp light comes on for the first time so I trust my dealer when he asked me to wait before I buy a mountain max rear exchanger. I will keep you posted. I spent morre time shoveing snow onto my running boards than getting unstuck and I have sent many email and survey notes to Yamaha too