He's probably talking poo. I checked mine myself at 6k because it was noisy - both set of valves were too loose, the exhaust side worse. Bike much quieter as a result. Checked them at 12k, both sets spot on in the middle of range (exactly as I set them at 6k). My suspicions are that they were set loose at the factory? I am about to check them again at 18k to see if that's the case - the motor is still quiet so I expect them to be within limits... the bottom line is, with correctly set valves the XT motor is a quiet one.

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