So i just got a 2009 RZR 800 S about 6 months ago, i love it! But it recently started giving me some idle/stalling issues. It all began 1month ago on our honeymoon in Moab Utah. RPM dropped down to between 750-850. I would seem worse the longer you ride, and eventually at Idle the RPM would get so low that it stalls. Took it to a shop down there, they checked TPS, cleaned air filter, checked fuel pressure – 38 PSI, tightened a loose spark plug and charged battery. The next day it started around 950RPM then dropped again. Since then i replaced spark plugs with NGK, replaced battery with Odyseey PC925, and taken it to Polaris. Polaris couldn’t figure it out until i suggested disconnecting the DynoPro power commander 3, with it disconnected RPM climbed to 1060RPM.

I thought it was fixed, went riding today, started out great, then within an hour RPM dropped into 800s, then 700s and started stalling at idle and became hard to restart without throttle.

Any ideas? Maybe TPS is bad? Fuel pump giving issues when hot? Belt?