Hey guys, can I get some help from the seasoned vets?? My 96 Polaris Magnum 425 4x4 has eaten the camshaft, or so I think. Can anyone give me some good advice as to how to inspect it to determine if its bad? I understand I have to take my valve cover off, but thats where I start to loose it. I have heard that the engine must be TDC but I am not to sure how to verify that. I suspect I have a bad lobe so any info related to this will be very helpful, its almost hunting season and I need to get this quad moving. I have only owned polaris quads and I am starting to look into other brands, this polaris just cant keep it together for long.

 

Take the valve cover off, you'll see the rocker arms, cam and cam chain, roll the engine over and the rocker arms will move up or down to open the valves, if the cam has a bad lobe one rocker wont move as much, you should be able to look at the lobes on the cam and see the one thats worn.

 

Does the engine have to be TDC before I remove valve cover? Or is that when I start removing the rocker arms?
Can I remove valve cover and start engine? Or do I just pull start slowly and watch the valves actuating?

 

Remove spark plug,then valve cover. Easier to turn over with recoil slowly. Check exhaust lobe in center,if bad,usually wont have any lobe left at all! Could just need valve adjustment if lobe eliptical and not worn. To check for clearance if cam good, align cam sprocket locating pin at top center of head,should have .006 clearance on intake and exhaust valves.