I hear alot about the cam problem on the 500s and thought I would add a pic from my scrambler to show what happens to them.

The middle lobe is the exhaust. This machine still ran just no power and popping problems.

 

Good example,I saw enough of em over the years! Thanx for posting so the 500 owners can see for themselves! P.S. Like your avatar OPT

 

Thnx. If any of you have a unanswered question this is the guy to do it. I've seen you answer almost every tech question out there, great work! Heres one for you, the decompression system on the cam: are you supposed to prewind the spring? Would have a pic of it installed correctly?

 

The spring is already pre wound. All you have to do is hook the small end under the cam stop pin,the longer end goes on the detent lever. Then you should be able to push the detent lever and it will retract back. Wish I knew how to show pics from the manual. Could be some videos around on this also. OPT

 

Thanks for the pics. Was this cam issue only a problem on the non HO models?

 

That and the old u-joint drive shafts on the 96-98 model Sportsmans.Expensive if you didn't keep em greased and had to replace the entire shaft because of damaged yokes (about $425 per side) Other than that the 500 was and still is a good engine whether it was in the Sportman,Scrambler or Magnum. Just my old OPT

 

Did we get some kind of fluke? My dads 97 Sportsman 500 has 7500 miles on it and the motor still runs like the day he bought it new.

We do change the oil frequently and only use synthetic 0w-40.

 

I found some that had good maintenance have the cams go out,others that didn't have as good care are still running around.I think there had to be different batches of soft heat treated cams mixed in with stronger cams. I just started checking all the 95-99 Magnum 425 and 500s and the 1996-2000 Sportsmans and Scramblers when they came in just to be sure.Looks like you have one of the good ones with that kind of mileage! It took Polaris until the 2001 HO engines to get rid of this problem. OPT

 

And to add to this they used the same cam for years which I found to be strange, I used a cam from a 2007 and mine is a 1999

 

I am an old retired fleet mechanic. Back during the 70s we had the same thing happen with Chevy cams. No rhyme nor reason, all were treated the same as far as maintenance went but some would come up with a bad lobe and needed changeout. Seemed as if they had the problem conquered about 1980. Probably had to do with heat-treatment & Quality Control.

Fred