2010 xp 550 / Recently my muffler has rusted out and more holes are showing up. Now my idle is higher at start up and unit wants to creep. Is the rusted out muffler causing the motor to run freer and trying to engage clutch or do I have a clutch issue ? 3800 miles
It is either the muffler with uneven exhaust gas flow, or oxygen sensor.
Try replacing the muffler with a slip-on, they are not too costly: https://www.powersportsid.com/quadbo...180018086.html
If no, check the sensor (I cannot comment on how to do it, though).
Good luck, man.