Issues with Belt

[DTro]

Is it possible to stretch out a belt and make it too loose?

Here’s why I ask. I’ve noticed that ever since I had a little incident that forced me to remove the belt and have a tow. I’ve noticed a lack in performance, it doesn’t seem as snappy and feels like the belt isn’t catching or almost like it's slipping. It will eventually get up there and go, but the “snap” is gone and seems to be hitting a higher RPM.

The guys that helped me out, just took a large screwdriver and levered the belt out of the pulley and worked it around. I’m learning as I go, so I don’t know if that was the proper way to remove the belt or not. I put it back on the same way.

Is there something I can check to make sure everything is how it should be? Is there a spec for tension and wear?

Anything else that would cause this symptom?

[superbee]

Put your spare belt on and see what it is like. It is possible that your other belt is damaged.

[Black_Bay]

No that wasn't the way to remove a belt. You need to move the sheeves apart on the secondary clutch. That will give you enough slack in the belt to take it off the secondary then off the primary clutch. By prying it off and back on you probably stretched it enoutgh that it's slipping. I suggest putting a new belt on and I bet your sled will run like it did before the incident.

You can measure the belt deflection by putting a straight edge on the belt while it's on the sled and pushing down on the belt with your finger between the clutches. The measurement is your deflection. It should be within specs which vary for different sleds. Check your manual for that.

A little trick with a new belt is to run a scotch bright pad on the belt edge where it touches the clutches. Wash the belt in soap and water after that and dry it before putting it on the sled. It's the clamping forces of the clutches on the belt that make the sled move. So a new shiney, slippery belt won't give you the best performance possible. Slightly scuffing and cleaning the belt will help it last a little longer too because it's not slipping.

[DTro]

Thanks for the suggestions guys!

[hanson]

Your drivebelt also wears on the sides of it over time making it narrower. This causes your gear ratios to shift a bit which is why a new belt makes the sled snappier.

[MN Mike]

Chris is right, as your belt narrows it rides down in the clutch further and mess's with your ratios. I know on Cat's you can take your secondary clutch off, pull it apart and remove some washers in there between the two shieves, what that does is it will narrow up the clutch and bring your belt back to the top again. I would always shoot for the belt to be 1/8" or so above the clucth shieves. I'm not sure how adjustable Polaris' are though, maybe someone else can give some info there.

Mike

[fishingforester]

Good info from all responders. Not trying to hijack the thread but I have another belt performance question. Last year, I had to tow a sled a little ways with mine. I did smell a little burnt rubber, but not an excessive amount. Now when I slowly get on the gas, there is a little hitch in my giddyup, sled kinda lurches forward with short, jerky movements. Get on the gas solidly, and no hesitation. I'm guessing I probably burnt some flat spots on the belt. Do I need to change the belt, or just leave it be and change it when/if it fails? FWIW, I have a 600XC. Thanks!

[Deep_Sinker]

The guys that helped me out, just took a large screwdriver and levered the belt out of the pulley and worked it around. I'm learning as I go, so I don't know if that was the proper way to remove the belt or not. I put it back on the same way.

[MN Mike]

fishingforester,

I think you are right, you probably burnt your belt, you should be able to see it if you can feel it when you drive the sled, I've burnt many of them and it doesn't take much to burn a spot on the belt.

I would change it asap, if the lurch goes away, throw that belt! you can do some serious damage to your engine if you continue to run it.

Mike

[fishingforester]

Thanks guys! To answer deep_sinker, I did have the carbs cleaned last year, and the jerky movement started right after I had burnt the belt (which I now see I failed to mention in orig post, inadvertently made it sound like it just started this year). The fuel suggestion is plausible but, having experienced what I was trying to describe, I am pretty sure the issue is in the drive system.

Mike, you answered the question I was most concerned with--whether I could cause other damage by running a damaged belt.

Thanks again.

[straydog]

""Originally Posted By: fishingforesterNow when I slowly get on the gas, there is a little hitch in my giddyup, sled kinda lurches forward with short, jerky movements. Get on the gas solidly, and no hesitation. ""

My wifes sled was doing the same thing, I was going to temporarily switch belts with my sled to make sure that was the problem before I went and bought a new one, and when I took it off I found some coggs missing on the inside of the belt. It probobley was going to start peeling apart pretty quick.

[DTro]

Well, I threw the spare on there tonight and that seemed to have helped quite a bit. The original belt was riding below the top of the shieves and quite a bit of deflection. Can you really stretch out a belt that easily?

I just took for a little spin after moving some snow tonight, too cold to go on an extended ride, but upon returning I checked the belt and it was about 1/8th above the shieves.

Thanks Guys!

[CraigM]

dtro, I doubt that just yanking on the belt like you mentioned would cause it to stretch like that. The motor/clutches put a lot more stress on it than that. Probably a combination of things such as the belt slipping, which will cause it to wear prematurely. If you were to mic it I bet you would find that it is narrower than spec more than being stretched. That would cause it to ride lower in the shieve. A screw driver is a bad way to remove a belt though.

Fishingforester, If you burned the belt, you also probably either left some residue on the clutches or polished the shieves and the belt is no longer gripping properly. They need to be cleaned with some brake cleaner and a scotchbrite pad. Lightly rub the pad perpendicular to the belt direction (out to in, not around) on the clutch surfaces and it will grip much better.

[fishingforester]

Thanks straydog and Craig. Wish I had a heated garage...

[Shack]

I have found in the past, when someone is new to a sled and especially new to sledding, a used belt (I am sure the one Dtro took off is the one that came on it and had some miles on it) can wear out quick.

Belts are made to wear and go out.

I will give Dtro this much , he has not crashed it yet, hurt him self, fixed some issues. By the end of the season, I would consider him a true sledhead.

[elusivecrappiecatcher]

Also make sure when you do get a new belt you break it in. MANY people over look this.

Wash the belt with a mild sope, like dawn or something. Dry it let it sit for a bit. Put it on and get the track off the ground. And rev the sled so the belt goes all the way top to bottom of the clutch.

NEVER just ride it after cleaning you can ruin it quick! Most racers do it this way.

Also make sure your clutch faces are clean and they are aligned.

Best belt deflection may not be 1/8 above shieves. Get the track off the ground and the best deflection is when the track barely moves off the ground. If it bareley moves sitting at idle you are good to go!

[DTro]

I went for an extended ride today and it just doesn't seem to be tip top.

At 1/2 to 3/4 throttle I can hear the RPM's increase but no increase in speed. Almost like something is slipping. I think my top speed is off a bit as well. I was only able to get 60-65 where I was getting maybe 75 before.

I'm not going to worry a whole lot about it, probably some kind of clutch adjustment or cleaning issue I'm guessing.

[2thepointsetters]

NEVER just ride it after cleaning you can ruin it quick! Most racers do it this way.

Race belts are not just thrown on and ran. I know mechanics that will go through a whole box of belts and only pick one or two if that. The width and lenght one every belt is very different even with the same part number. Some racers will break belts in before hand. (also guys will use one belt to ride to staging and then switch to the one they will run.Maybe this what you might have saw) race belts are also softer compound rubber. I guarantee they are not ruining belts. The holeshot is everything.