Took my 09 RZR S to SMORR yesterday...one of the most dusty places ive ever been!!! Now before the trip i cleaned my K&N air filter within an inch of its life..and really it wasnt that dirty..the outerwear was dirty but when i flushed the filert its self it was suprisenly clean...anyway, it started the day off at its usual 1100-1150/60 RPM at idle.....as the day went on and it got hotter i noticed a lil sputter at low speed and reverse, but absoutly no power loss when on the throttle. At mid day and very warm outside (and dusty) i noticed the RPM's at 1000-940/30....would go back up to 1000-1050 when the fan came on......towards the end of the day i seen it dip into the 700-800 a few times...still with no loss of power. I checked the filter when i got home that evening......the outer wear was pretty dusty and the airbox has fine dust in it..but the filter and as far as i could tell the intake was clean. went out to wash the RZR this morn and the idle was still at 900-950...anyone wanna guess why? It is all stock except for a Dynatec fuel programmer that was on it when i bought it.