Have a neighbor with a Ranger 500 efi. The unit will randomly lock the throttle in place-brakes applied will slow the unit but it still tries to go at the set throttle. The trans cannot be shifted into neutral either--it seems to be locked as well. The only way to shut the unit down is to turn off the ignition. After the unit rumbles to a stop, the unit can be restarted and run with no issues for a time, but the issue will pop up again randomly.
The throttle body was inspected and is clean-the throttle cable is free of any bends/kinks, and works smoothly.
Can anyone offer a possible culprit for this issue?
Thanks,
Gary

 

Found on another forum similar issues reported by members
Looks like the "idle stepping motor" is the culprit--unplugged this thing and the rig has not had the problem again--kinda makes one wonder why Polaris put this thing on in the first place

 

Ok --the disconnected stepping motor seemed to cure the lock up at 3500 rpms for a day or two--then the unit started having idle issues. We ordered after market stepping motor--the unit seemed to have responded to the new step motor ok --no issues for a couple of days, then it started to exhibit the same throttle lock-up at ~ 3500 rpm--got a new Throttle position sensor(TPS) -The rig started to buck and bronk at elevated RPM (3000+) and refused to idle--The old TPS had NO dead spots in the rheostat-appeared to be fine. Plan is to re-install the old TPS and get a new step motor--
Anyone with similar issues with solutions would be greatly appreciateed--

Gary

 

So I got this 2012 sportsman 500 and it rubbed just fine a few days ago when I rode it but when I was riding whtih my buddy it just didn’t want to move it was in gear it started just fine but it bogged down when I tried to go I checked the oil it was alright i just don’t know I look at the carb it won’t open the flap all the way it bogs at about 3000 rpm can someone help me