Sled moves 50ft then refuses to move

will it move if you lift the front end...are the ski's digging in...??

When you hit the end of its movement what do you see happening under the hood?
Is the primary clutch spinning but not engaging the belt?
Is the belt spinning and not turning the secondary clutch?
Are both clutches spinning and the track isn't responding?

is that the model with no chaincase, clutch on the driveshaft?

KKRRSS said:

Hello,
My son started up the 85 SS Polaris 440 air twin, and it'll run 50-75 ft on the grass, then won't move any more.
I can lift the back end and it'll spin the track.
Cleaned the carb, that was all good.
Moved track and driven pulley by hand, it's not binding up.
So, wondering about the clutch.
I am new to clutches. The sled ran fine on the snow, but on the grass, no go.
Wondering if I need to go through the clutch.
If so, what identifying marks do I need to post here to help get some guidance on going through the clutch?
Thank you,
KRS

Click to expand...

Try opening the gate so he can get through it. LOL.

But seriously I think this sounds like the clutches need to be cleaned at the very least. I think they are starting to upshift and then cannot backshift properly so it bogs the sled down. The grass is harder to push the sled on so that is why this shows up now instead of on the snow. I had an 86 SS440 and I know they don't have a lot of power to overcome dirty clutches etc.

Do you have a puller for the primary clutch? If not you can get at the spring by removing the 3 bolts holding the cover on. Make sure you mark the cover and the clutch sheave so you can reinstall the cover in the same position as it was. It was balanced at the factory so needs to be reassemble the same way. There should be a white spring on the primary but may have an orange if it was run at high altitude. Make sure the weights pivot freely on their pins. Wash everything with brake clean.

The secondary can be removed without a puller. Remove the bolt and it should slide off. Pay attention to where the washers are on the bolt and also the spacers behind the clutch on the shaft. Once you have it off remove the snap ring and washer. There is spring tension involved so push down the helix while you do this. Try to take note of which hole the secondary spring is in but if you can't the factory setting was #2. Inspect the ramp buttons and replace if worn. Clean the helix and polish the ramps with fine emery cloth. The helix should move freely on the shaft without binding. If it binds you may have a worn bushing which will need to be replaced. When you separate the sheaves you should see 2 thrust washers on the shaft between the sheaves. They are used to adjust belt deflection which should be 1.25" when you push down on the belt with the clutches in the idle positions. To check just get a flat edge and lay it across the top of the belt from clutch to clutch. Push down and measure the distance between the straight edge and the top of the belt. Don't push down so hard that you force the belt to open the clutch sheaves. If you have too much belt deflection you remove a washer. You need to have at least one washer at all times. Clean everything in hot soapy water and rinse with clear water. Dry and reassemble clutch. Don't use any lubrication on any parts as it just collects belt dust and will gum up the clutch. Reassemble the clutch, install the spring in the helix and tension it 1/3 turn. Install the helix key, washer and snap ring. These sleds run at only 6000 rpm because of the direct drive. You can adjust the rpm slightly by changing the hole position of the spring in the secondary. Increasing spring tension one hole should increase rpm by about 250 rpm.

If you don't find anything wrong in the clutching though at least you will have them in good condition for next year and you will have learned something as well. Better to do it now than when you want to go sledding the next day.

One other thing that has not been mentioned is jetting. The temperature is a lot warmer now so you will be running very rich which will cause a loss of power. I don't know what altitude you are at but chances are that you will have to decrease the main jet by at least 3 sizes from what is in there.

^good stuff up there, i would research the specs on that set-up, is the clutch supposed to float a little, like newer models with chaincases..., ect..
but yeah, without the gear reduction of a chaincase, its gotta be just right ill bet to get movin on dirt.

KKRRSS said:

Well, tore my meniscuc in my knee. I'm out for a month or two.

Click to expand...

Looks like something else ran fifty feet and quit moving. Mend well.
550iq

It may not be the recommended method, but with the belt off, start up the sled and with a steady throttle thumb, increase the rpm's and watch the clutch engage fully, then let it back to idle. It should operate smoothly, however without resistance on it, once the spring pressure is overcome, the sheave should jump pretty quickly.

Don't stand in line with the clutch in case something comes out of it.

If this passes, the secondary may be hanging up not allowing the belt to drop all the way down. With the belt off, you should be able to spin and push open the 2ndary clutch by hand. You may have to pinch the brake to keep it from rolling while you are doing that.

Try a new belt, those things were really fussy about the belts and belt deflection. And also check the clutches, always a good idea.

again...steel ski's on grass...is there any improvement on snow..??

The belt comes off the secondary clutch very easy? Is the spring and helix installed correctly?

It sure sounds like you have the wrong belt on there or the secondary is not closing or it binds before it can be fully opened during operation. A drive belt doesn't stretch with use. At idle position is the belt sitting up at the top of the sheaves? How much belt deflection is there? Did you pull the secondary off and look at the spring and helix etc?