The originals weren't heat treated properly for a bunch of years.Some failed,some didn't.If the cam is cheaper than oem and they guarantee it,get this cam along with ordering a new exhaust rocker arm. Unusual for a 2001 to flatten a cam,but anythings possible. The easy way at least for me was to have the cam at tdc that is with the sprocket index pin straight up,center of the head.Make a mark on the head as the reference point. Remove the tensioner,thermostat housing(you have to remove it to access cam removal cover) Without moving the crank shaft remove the three cam sprocket bolts(impact gun allows you to do this without moving the crank!)Let the sprocket and chain drop down into the head cavity out of the way.Remove the cam rocker supports,rocker arms,then remove the cam cover and slide the old cam out. Install the new cam with lobes down,make sure the detent spring and lever are correct,pull up the cam sprocket,and install on the new cam. If you have to move the sprocket inside the chain or even jump teeth on the lower crank sprocket to align the index pin correct this is okay,just DON'T move the crank shaft! Once sprocket is on,replace the cam removal cover,thermostat housing,rocker arms and support blocks.Then replace the tensioner and bolts with the plunger pushed all the way back in(it will self adjust later) adjust the valves,then slowly pull the recoil. The tensioner will then adjust slack on the chain,then you can replace the top cam cover. Top off the coolant you lost from the thermostat housing removal and leave the radiator cap off.You also need to clean the screen in the oil tank,replace oil and filter,clamp off the tank vent line and crank it up. Let it idle several minutes,then remove the vice grips from the tank vent. You may or may not hear a "hiss" of air when you do this. Also make sure you run it again to make sure any air is purged from the cooling system. If you don't like this way you can try to keep the tdc mark on the flywheel with the mark on the recoil cover and time it up,kinda hard to do, OR as you do when you rebuild one,remove the recoil,flywheel,stator,align the lower crank sprocket mark up with the engine case mark along with having the cam sprocket index pin dead center of the head,then replace the stator,flywheel,recoil,etc. Several different ways to change a cam. This way just the easiest for me. Plus don't pay any attention to the cam chain plated links. These three links were just for ease of install with the stator off and once the engine turns over the links don't line up again..Hope this helps as my fingers are tired!

 

Thanks for the info!

Basically it doesn't matter if the chain comes off the bottom sprocket(crank) as long as the new cam gets installed in the EXACT same position as the old one(in relation to the mark you made on the head).

Does the gas tank need to come off or can I work around it?

I've got a cam and rocker ordered off E-bay, should be here in about 10 days. As much as I like my local Polaris dealer its was $100 cheaper AND faster off E-bay. Polaris closed their Canadian warehouse and now anything that the dealer doesn't have in stock takes 1-2weeks depending if you missed the weekly shipment cutoff.

 

Correct on the cam install! If you have good hands you can work with the tank in place..

 

Thanks, I'll let you know how it goes after it arrives.

 

I have a 96 sportsman 500. The cam is dead. I'll be installing one as soon as I get one here. Thanks for all the help.

 

OK I got my cam shaft and rockers in place and bolted down with valves adjusted. I wasn't sure if I had to do anything special with the chain tensioner. I removed it by taking the 2 bolts out that hold it down. Do I have to do anything with the bolt in the center as it goes back together?
Thanks Tim

 

Yes! If the tensioner is out,loosen the 10mm bolt in the center and slowly remove it. There's a spring behind this bolt. Don't loose it.. Push up on the lip of the tensioner ratchet and push the tensioner all the way back in. Bolt the tensioner body back to the cylinder,have it at tdc,reinstall the spring and bolt. Takes a little pressure to do this and the tensioner will ratchet out and touch the chain guide. Pull the recoil over slowly and the tensioner will readjust to the cam chain slack. Items #1-5 Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse
The tensioner needs to be installed last after the valves are adjusted at tdc.

 

OK Thanks I figured I had to do something with it. I played around with it before I posted up and saw that it needed to retract. I put it back on before I saw your post. Here's how I did it. I loosened the bolt with spring and backed it out a good bit. The plunger would then retract about a good 1/4 inch. The tensioner bolted down without much resistance. I tightened up the center bolt and turned the motor over by hand.
Thanks for the help. Tim

 

Alright this thing is really starting to kick my butt. Been working on it off and on over the winter. Got a new cam in, fired it up and it was REALLY stiff to turn over and seems low on power and not making full RPM. Started checking things, decompression lever lever seems ok, chain looks right, valves clearance in spec.

Strange thing I'm noticed is that I cann't get the engine to stay at EXACTLY TDC. I pull the cord to line up the mark in the hole and just as its about to line up I fell resistance(like compression building) and then the engine rolls over a bit on its own past the mark. WTF?!! The spark plug is out and I even took the valve train completely off just to make sure that it wasn't pushing on a valve.

A this point I'm thinking I either have a sheared flywheel key or bad replacement cam.

Any suggestions?

And to top off my day I put a new battery in the daughters Outlaw 90 and the little black box(rectifier?) under the seat promptly started smoking!

 

In your case just best to pull the flywheel(check for a sheared key) then the stator and time the engine up per the manual instructions. Plus not uncommon for the left threaded slotted crank sprocket nut to back off and cause this key to shear or to jump cam timing. If both the flywheel key and crank sprocket key are ok, just align the mark on the crank sprocket with the mark on the case bottom(tdc) then just have the single plated link on this mark, align the two plated links on the two dots on the cam sprocket and the cam will be at tdc.Adjust the valves,install the tensioner,pull the recoil over slowly and the tensioner will adjust itself. When I installed cams,I pulled the plug, had the cam sprocket at tdc and made a mark on the head in line with the sprocket index pin, then removed the sprocket with chain and just let both drop down. Installed the new cam,pulled up on the sprocket and chain(jiggled chain slightly around the crank sprocket if needed WITHOUT moving the crank) so the cam sprocket index pin would line back on the mark I made,then installed the three bolts on the sprocket,then bolted down the cam,adjusted the valves and installed the tensioner.This was my way after doing so many of them,but may not be the best for others that haven't done this before.Item#17 keyed crank sprocket,#18 left threaded sprocket nut. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse