I have a 2011 Polaris Ranger 800 XP. Recently it started losing power and the check engine light comes on. YOu can ride for maybe 10 minutes then it starts losing power and the light comes on and you have to turn it off. Once it sits for about 10 minutes you can go a little further and then it starts losing power again. I installed a new air filter and there is little spots of oil on it. Any ideas whats causing this?