So I have a 500 Polaris (non-HO) that started running terrible several years ago. It has sat for a while and my father (he owns the bike) had his employee pull it apart and realized the cam had failed.. Journals were badly worn. His "Man" Is not a mechanic , but like me can get around a motor with the right help.
Anyhow - He installed a used HO cam and carb. It seemed to run well for a couple months and then the same issue, sure enough cam is gone again..
Ideas on what could be causing this ?

I might give this thing ago myself , cause he is talking about selling it locally to a guy for $500.. Its still in pretty good shape.

 

Did you replace the exhaust rocker arm when you replace the cam? If not, it could have been the cause of the wear on the lobe on the second cam. Plus are you sure what year model the used cam came out of?

 

Also only use Full synthetic 0w-40. Get that oil to the top end on cold starts as quick as you can.

 

Did not replace the exhaust rocker arm..
I thought that same thing after the other cam failed.
I didn't do the work , so am not sure of anything, just trying to get an idea if its worth throwing another cam at it !.

 

Really ??
I have never had to run FULL synthetic in anything to save parts ?

Kyle

 

This engine requires full synthetic to get to the overhead cam quicker and lubricate it better. Polaris has been using synthetic from day one! Replace the cam and exhaust rocker arm,use either 0w40Mobil1,Amsoil,etc. You can even use 5w40 T6 Rotella from Wallyworld or any good 5w50 synthetic oil. You may have had two problems, a scarred up exhaust rocker arm and wrong oil causing the second cam to go out.

 

Where is the best place to buy the cam and rocker arm.
Keep in mind the HO carb has already been installed !

Kyle

 

The engine is a dry sump,not the common wet sump. the oil is in the exsternal oil tank not the motor,s crank case so the 0w-40 will flow quicker on cold starts to the top end.

My dads 1997 500 has 7000 miles on the same cam, my 2001 has almost 4000 miles now.

Try another cam rocker still cheaper then a new or used ATV. I think they only offer the high duration H.O cam as a replacement now. The H.O cam works with the non H.O 34mm carb anyways.

The Fuji built single cylinder Polaris motors are their strong point not there weak point,but there fussy on what oil they use.

 

Here's about the cheapest place I've found online. I ordered a cam and exhaust rocker arm for a friends Ranger about a year ago . Quick service.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse I've listed the 2001 model as the 2000 and below models call for the non HO cam #3066212(but has been strengthened) The only difference between a non HO cam and a HO cam is the duration,the lobes are the same height and you can run either one.

 

Thanks for the link.
What is your opinion on the aftermarket cams and rockers available ?

Kyle