First of all I'm new to the forum and just like to say HI - lots of great info here

I bought a used 2008 Polaris 500 touring with 2000 miles and it runs great, starts great and seems to be good machine except.....

Here is Utah we go riding above 10K feet and the ATV goes into crawl mode - will only go 5 mph and cut out and dies if I try to go any faster - it will restart easily and stays in the "crawl mode". When I get back to lower elevations it comes back alive and runs great again.

I heard of a "wire" under the seat in the breather box that might be an issue but was hoping you can point me on how best to diagnose the issue.

Many thanks for whatever info that might help get this machine moving on the mountain.

Craig, Murray UT

 

First off an efi machine if working right should compensate for altitude and temperature with hardly any problems. The sensor in the air box is the temperature sensor. You might clean it off if it has an accumulation of dust and dirt with compressed air. One other problem area is the foam collar support for the air box air intake tube and intake tube for the clutch. If it was to ride up on the tank area it could partially block the air intake and cause it to run crappy.Item#8.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse the air temp sensor isn't shown in the air box,but looks like this.Item#19.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse If the foam collar isn't riding up and the sensor is clean and still goes into limp mode,then it might be time to have it reflashed/recalibrated on Digital Wrench plus it may be able to find any other problem area such as a harness wiring or sensor problem fault.

 

Thank you very much for the detailed info - I'll check out those parts and I appreciate the great response!