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Primary Clutch doesn't move much

16K views 58 replies 9 participants last post by  MrFrog 
#1 ·
I have a 1994 Arctic Cat Cougar snowmobile. I got it from a friend who hasn't used it in 10 years. The engine runs fine, but the clutch won't engage. I took off the primary outer cover and then removed the spring, but the primary clutch only moves about a half an inch. I have tried spraying kroil penetrating oil on it but that doesn't seem to help. It has a fair amount of rust on the shaft too. Any thoughts? If possible, I want to avoid taking the clutch off. Thanks in advance.
 
#4 ·
The primary clutch is a DRY assembly. Any time you add grease, oil, or anything with moisture, you're inviting dust and little bits of whatever to collect there and make things even worse. KCCATS is dead-on with the no oil comment here.

As already stated - you will need to remove the clutch. Period. Restoring it to proper operation can not be done on the machine, and the alternative of swapping it for one that works properly obviously requires removal of the bad one.

If you go the route of refurbishment, be sure to use someone that knows what they're doing, and expect to pay more than you would for a working used clutch. If you opt for swapping the clutch, understand that a working used clutch is not necessarily a working PROPERLY used clutch, and you may need to get it worked on at additional cost anyhow.
 
#5 ·
The Comet clutches used on that year AC sled are pretty weak, I would not spend any money rebuilding it. If a simple cleaning and sanding so the movable sheave moves freely doesn't solve your problem, replace the clutch.

I would get at least a 9 post Arctic Cat clutch to replace it with. Even if the 9 post is needing some help, it's worth the money to fix.

The newer 6 post Cat clutches are even better, but will cost you more bucks.

You will need to get a puller to get your clutch off or take it to a dealer to have them remove it for you. It shouldn't cost a lot to have that done. I would opt to get a puller and learn how to use it. Removing clutches is a yearly maintenance ritual for most sledders that take care of their sleds.
 
#7 ·
Ok. I was taking the belt off the primary clutch and once I got it off I realized that it had freed the clutch somehow. It moves freely on the shaft now, but when I put it back together, it still doesn't move when I rev the engine. Two of the three weights are just a little sticky. Would that matter? Why else would the primary clutch not be moving? Thanks.
 
#8 ·
Sticky weights will keep it from engaging. The way that the clutch generally works is like this:

The motor spins the clutch. At idle, and up to a certain RPM, the spring holds the moveable sheave in place "hard enough" that the rotating force can't overcome it. It stays open.

As the rotational speed increases, the weights will start to move and apply force against the moveable sheave. The faster it turns, the harder the weights press, and the clutch closes in accordance with the RPMs.

If the sheave is unable to move along the shaft, it won't close properly or may have issues properly opening all the way. But, if the weights don't move freely, the rotational speed will not translate into lateral force to push the moveable sheave inward and close the clutch. All of the moving parts in a primary clutch need to move smoothly and freely for proper operation.

Pull the clutch and spray it down with brake cleaner to get all of the belt dust off of it. I recommend NOT doing this with it mounted to the motor because the brake cleaner can find its way onto other parts and damage them (like motor seals).
 
#9 ·
If you don't have the correct puller, you can still (likely) remove the cover and spring.
What I have done is to remove 2 of the 6 bolts and put 3 that are an inch longer back in and then remove the other 3. Now there wont be any tension on the spring.
With the cover off and the spring out you can easily check the bushing to see if it wobbles?
As well as watch how the arms move.
But still your best bet would be to find a better clutch to begin with.
I have all the specialty tools to rebuild the clutch and my odds aren't good. About half will strip the threads out!
 
#10 ·
Ok. So I took the clutch apart and cleaned the weights and rollers so that they move smoothly now. Without the spring on, the sheave moves freely on the shaft as well. Why else would it not be moving? Should I be able to push the clutch inwards with my hands with the spring and cover on? Thanks.
 
#11 ·
Check the rollers for flat spots, they can bind and keep the weights from moving the movable sheave.

There's pretty significant pressure in the spring, if you have really awesome grip strength, you may be able to compress the spring a little. The yellow/green spring is rated at 114 lbs. initial force, and 267 lbs. fully shifted force.
 
#12 ·
Ok. So I have the clutch cleaned up pretty good, and am waiting to test it out. There are no flat spots on the rollers.

I was running the engine and realzied that there is condensation or something dripping out of the exhaust (there is a fair amount). Why would that be? It doesn't smell much, but it smells a little bit like gas or something. I don't know why that would be coming out of the exhaust. The engine itself runs ok, but I don't want to run it that much without knowing what is coming out of the exhaust. Could it have anything to do with sitting outside for 14 years? Also, when I take the spark plugs out, they are both pretty wet. I have the mixture screw set to manufacture specifications. Any thoughts would be great. Thanks
 
#13 ·
It's not at all uncommon for condensation and unburnt fuel to drip out of the end of the exhaust pipe until it gets hot.

Right now, you're running -very- rich because it's jetted for much colder temps. Wet plugs (and additional unburnt fuel in the exhaust) are to be expected. You won't be able to adjust the carbs for mix until you hit operating temps and can run plug chops.
 
#16 ·
Would the warm weather also make for bad performance?
Until / unless you get the exhaust hot (which requires operating the motor under load), it's likely going to drip. There's moisture in there and unburnt fuel. It's running VERY rich because of the warm temps, so there's unburnt fuel in the exhaust.

Plug Chops: Take the sled out and drive it, constant throttle, for at least 30 seconds. Without letting go of the throttle, hit the kill switch and let it coast to a stop. Pull the plugs and check for color and wet/dry.

Do this at each of 1/4, 1/2, 3/4, and full throttle as those are key points in the travel of the carb slides to help with adjusting the mixture for each point.

As I said earlier- VERY rich with the warm temps, do NOT try and adjust now or you'll toast the motor when the temps drop as it will be running way too lean at normal "winter" temps.
 
#18 ·
Ok, so I tested out the clutch and it still doesn't engage at all. The rollers have no flat spots, the weights move freely, and the shaft is smooth. Without the spring on, the clutch moves smoothly down the whole shaft, but once I put the spring on and try to get it to engage, it won't move. Any help would be greatly appreciated. Thanks. Would an old spring cause it not to engage?
 
#23 ·
Or over-rev the motor.

It's -possible- that the spring could be corroded badly and that could keep it from compressing.

Do you have a tach on the machine? If so, and you're reasonably sure it's accurate, I would rev the motor to about 5500 RPM max. If that clutch still doesn't engage, something is wrong. Even if it had a clutch kit for racing or something, it should start to engage by then. The fact that you can't close the clutch at all with the spring in it leads me to believe that something is not right with that spring.

If you have a scale and drill press, you can test the spring's compression force in a makeshift way. Put the scale on the bottom, stand the spring up, and use the leverage of the press to try and compress it. If you go beyond a couple of hundred pounds of force with no movement (use a ruler to measure), that spring is frozen.
 
#26 ·
So I tested the spring by putting a 2x4 on the spring on the ground and then standing on it( 155lb.). The spring does move and seems to be fine. I tested the clutch again and it still won't engage the slightest bit. I am so confused. Any other thoughts? Thanks again!!
 
#27 ·
Next area I would inspect is the weights. Be sure they're installed correctly, the correct weight, and they move freely. Assemble the clutch without the spring and swing the weights out manually to get a sense for how they move.
 
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