Ranger 500 LOW compression
 

Hi Guys a newbie here .I just purchased a2000 Polaris ranger 500 .It was running great then it started putting and stalling.Then It wouldnt start .Did a compression test and it only has 25 ilbs of pressure.Do you think I should go ahead a
nd take top end off .Prob piston rings?This a easy newbie job?Anyone have any advice ?I looked on you tube but couldn't find any vids on this.Thanks John

Check the exhaust cam lobe for any wear first. Common problem on a lot of 500 engines. Here's what to look for. Bad Cam Pic - ATVConnection.com ATV Enthusiast Community Plus average compression on the 500 is only between 55-90 psi on average because of the compression release built into the cam. Strange that the Ranger didn't get the HO cam(3085855) until the 2010 model. It used the old 3086212 cam that the Magnum 425 and early Sportsman 500 used.

Thanks Tech
 

Someone was telling me I can put some oil down cylinder and do another compression test if it comes up its the rings any truth to this? If so how much oil and what type .Thank You

The oil acts as a seal around the rings. My old 1981 ford truck had gas in the oil from pumping the gas pedal to often and would not start due to low compression. I changed the oil and it started right up.