back to the drawing board (CVT belt)

[supertoast92]

It's been awhile but I'm back with the same old problem again with the belt slipping on our Helix. This time I've made more observations. After about 10 minutes of riding and it starts to slip, I brought it back to base only to find more smoke coming from the CVT case, and the case was extremely hot to the touch.

I waited for it to cool down, took the filter completely off the intake and tried running it again. Oddly enough it's still slipping and overheating. So, the intake must not be the issue.

Any more ideas what it could be?

[joshstep1]

Could it be a worn belt?

[olderthan]

time to replace your belt
check your sliders and clutch at the same time
if needed would be a good time to replace or
repair as needed
olderthan

[supertoast92]

Well, that's the thing. The belt has nothing to do with it. We went through 2 belts in the past month, and something tells me that isn't the normal lifetime of a belt

[olderthan]

i would be checking the variator and clutch carefully for
sure then i would also make sure they are lined up to each
other sometimes you need a shim
i knew that you were having problems in the past
but i did not know that you had changed belts
olderthan

[supertoast92]

We should have checked the pulleys more closely last time we had the CVT open, all we have done is replaced the belt and sent it back out running, only to have it slipping after a few runs.

What exactly would I be looking for with the pulleys/variator? We have already replaced the clutch plate as well.

[olderthan]

make sure they are aligned to each other
take your variator apart and make sure the sliders are smooth
and that none are turned
olderthan

[olderthan]

did you put a new clutch spring with the new clutch?
olderthan

[supertoast92]

Nope, the only things we replaced were the clutch plate, the belt (couple of times), and the CVT gasket which is pretty brittle.

[BuggyMaster]

this is a long shot but it happened to us:

Any chance your parking brake lever at the brake pedal accidentally got kicked up and is slightly locking up your brakes causing un-needed drag? Can you roll the buggy freely when it is turned off?

[supertoast92]

That is a good place to start checking, but nope, rolls freely and parking brake isn't locked on.

[SYCARMS]

When you pull it apart make sure everything is clean and free of debris. Some times when a belt shreads,pieces of cord from the belt will get wedged between the clutch pulleys causing the belt to start out lower on the driven pulley which puts you into a higher gear. Also check the rollers for flat spots. Inspect both pulleys for signs of wear or bluing from getting hot. If one shows more over the other problem will likely be at that end.Make sure fan blades are not damaged or intake plugged. If you are driving hills in access of 25 deg. grade the cvt needs tunning. I can take just about any buggy and purposely break the belt by pushing it beyond the capabilities of the cvt tune. After making sure everything is clean, aligned ect. run the buggy on stands with cover off and observe the workings of the cvt looking for anything abnormal. TOM

[supertoast92]

Hey guys it's been a long while since I posted about this, thought I'd give an update. We tore the entire CVT area down to the shafts and inspected each pulley. I wiped the clutch and variator plates clean, nothing much was on them. So now since we're nearly completely stumped on what the problem could be, we have another theory. Could it possibly be that the clutch spring is too weak? It could be preventing the clutch from squeezing together tight enough, thus causing the belt slip.

[PatNY]

When you smooth the inside of the clutch bell to a glass like surface and the clutch pads... Then all you're doing is creating slippage more often and more heat which can lead to belt failures. Once the bell and clutch shoes heat up and glaze over they lose most of their grip.

Things you might want to try:
1. Use some fine grit sand paper on clutch pads and clean that glaze off
and then some heavier grit sand paper or emry cloth on the clutch bell

2. Heavier clutch springs for the clutch

3. Might need a new clutch, if the clutch pads are worn out

4. I would definitely check the rollers for flat spots (replace if necessary)

5. If sliders, make sure they are seated the correct way.

6. Take off the Variator and Clutch assembly apart and clean it well.

7. If the clutch bell shows signs of warping, scoring or fractures, it has to be replaced.

7. Use the correct belt size for your buggy.

[supertoast92]

Thanks for the suggestions everyone,
Today we decided to just go ahead and order a new clutch assembly, it should arrive sometime next week. The spring isn't labeled as an individual part in the manual, so we had to order the clutch as a whole. If this doesn't work, with the new clutch pads and getting the residue off the pulley plates, I'd be stumped as what else could be the problem. With the new parts we'll have new pads, clutch bell, and a belt. So hopefully this will be a permanent (well at least for a year or two) fix.

[chuckorlando]

Is your cvt stock? Why did you replace the pulley at first? Do you ride hills or mud? As Tom Syc stated, the wrong cvt set up will cause the belt to heat. Once it starts to slip it gets glazed and will continue slipping. Did you take the clutch pulley apart to inspect for snags? Is this a gy6? If so why not just order a performance or stock spring?

[supertoast92]

CVT is stock, the part lists the entire clutch pulley assembly as one part, so we just ordered a new clutch. We couldn't order just a new clutch spring as there wasn't a specific part number. Wasn't terribly expensive. It's a GY6, standard Helix from Tractor Supply.

[chuckorlando]

Next time give Tom a call. Heck I would have mailed you one for free. You can call any scooter or buggy dealer and just ask for a 1000 rpm main spring. You may want to look into some 10-12g rollers or sliders and a yellow main spring. Or a bigger sproket. This will gear your cvt a bit lower and take the stress of your belt

[SYCARMS]

Chuck made a good point. If you read your owners manual it states that the buggy will climb a 25deg. grade. This is also assmed to be a person or persons of average weight. A 25deg grade is not alot when you realize it. Anything other than the normal driving as stated in the manual will require upgrades. Now with that said I have with stock cvt taken terrain with more than a 30deg. grade with 2 grown adults and have had no problems, but I know what the buggy will and will not take. For instance if I were to stop on a 30deg grade fully loaded and suddenly accelorate I would be overloading the cvy to the point of overheating resulting in something breaking. Lighter rollers and heavier torquespring will help the cvt run cooler. You first must inspect carefully all components of the cvt. A good way is to watch the cvt operate with cover off and buggy on jack stands. One problem I have seen several times is belt cord caught up in the clutch pulley. Visual inspection will not always show this. By running with the cvt cover removed you can than watch that the belt moves the entire range in both the clutch and variator. If you had cord binding the clutch pulley it would be self evident in that the pulley would not be opening and or closing completely and watching the belt movement would make this evident. Also you would see if you had a bent crank or clutch shaft.Even with the new clutch it is recomended you use lighter rollers and also a 1500 yellow torque spring. You will notice a good bit of performance. If you have any questions you can call me at 662-301-1563. TOM

[ckau]

I have to agree with Tom.The cvt is pretty well designed and a mechanical problem that continually burns belts is rare. Most can be attributed 99% of the time to driver error rather than mechanical failure. If your satified that the cvt is mechanically sound, then there is only one factor left. Not meaning to cut you down, we are ALL guilty of this. When I got my first buggy, I was totally ignorant of the capabilities of the machine. I fried belts and clutches. continually until I found the limits of these components. I thought I should be able to just motor through just like my truck or 4-wheeler. It took me a little while to learn when it was time to back off the throttle as to not fry the system. If you come to a steep grade or mud, the buggy slows and slips but not the rpms, your cooking the belt. If your revving up but not moving, your cooking the cvt. You have to approach obstacles with finesse and strategy. Pick your path before you get there. use speed and momentum, not power to get you through. I've witnessed a lot of people approach a log or a rock in the trail, run the front wheels against it then try to power over.This only burns the cvt! These motors don't have this sort of horsepower. Best solution is to pick another path or use suspension rebound to get you over. Rebound is a technique where you approach the obstacle at speed, come off the gas, tap the brake to cause the front end to compress then time the throttle to push forwards on the shock rebound. This causes the front end to bounce up and over with out losing forwards momentum thus taking strain off the belt and clutch. If the obstacle is higher than your ground clearance, you probably won't make it regardless of power or technique.
Once I learned what I could and shouldn't, I stopped burning belts. Even though I haven't popped a belt in years, I replace them about twice a season to be on the safe side. I still carry a spare while on the trails cause you just never know what your going to try next.

[supertoast92]

That could be why the CVT is messed up, but I drive this thing in a mostly flat yard and field. At most I climb a hill on the street that is 10 degrees. Maybe going from rest to full throttle didn't help much, but I never really did anything that involved climbing over obstacles or steep slopes. The hardest Ive run the Helix is during the winter, doing donuts and 360's and all that good stuff in the snow.

What I've noticed is that the kart takes off at extremely low RPMs, and it has a very high RPM the entire time I accelerate. The belt is probably slipping this entire time, but I think cleaning off the variator plates with sand paper and the new clutch assembly should fix the problem, along with hopefully our last replacement belt for a year or so.

The belt that came with it lasted for two years, which was up until I started having the troubles.

[SYCARMS]

Again if you were to put the buggie on stands and pull the cvt cover you will than watch the operation of the cvt. The pulleys should move simotaniously with variator end the belt rising to top and the clutch moving down. Also roll your rollers on something flat and watch for flat spots. Torque spring can be fatigued or broken causing the belt to drop too soon on the clutch. All this can be determined by watching the cvt work. TOM

[olderthan]

i would go with a 1500 spring &
10g rollers
should help
olderthan

[supertoast92]

Originally Posted by SYCARMS

Again if you were to put the buggie on stands and pull the cvt cover you will than watch the operation of the cvt. The pulleys should move simotaniously with variator end the belt rising to top and the clutch moving down. Also roll your rollers on something flat and watch for flat spots. Torque spring can be fatigued or broken causing the belt to drop too soon on the clutch. All this can be determined by watching the cvt work. TOM

Ok, will do this again, watching more closely. We have watched it operate on stands a few times, not noticing anything out of the normal.

[ckau]

Originally Posted by supertoast92

but I think cleaning off the variator plates with sand paper and the new clutch assembly should fix the problem, along with hopefully our last replacement belt for a year or so.

The belt that came with it lasted for two years, which was up until I started having the troubles.

It sounds like you are not abusing the buggy for sure. Don't use sandpaper on the variator surfaces. this will cause premature belt wear also. The rough surface will eat the belt down. The variator surfaces should be polished to a mirror finish. Use a buffing pad in a air drill with rubbing compound to clean the variator pullys. The slicker the surface, the better the belt travels and grabs. Polish/compound the clutch pulley surfaces also. Do use 100 grit cloth on the clutch bell to remove glazing. If the glazing is bad and the bell shows some blueing, start with 80 grit then give it a final polish with the 100. If there are just a few spots of blueing, the bell is ok. If the bell is totally blue or real dark in color. it means it got too much heat and should be replaced also. When the bell gets to this point, it doesn't matter how well you clean the pad surface, it will promptly glaze over and start slipping again.
Check your main clutch spring to insure it does not bind and the clutch pulley halves can travel in and out smoothly. A small touch of lithium grease is ok to use on the shaft and spring base cup, just enough to shine the pieces. You don't want grease to sling up on the pulley surfaces. Don't handle the pulleys with dirty hands. Clean every thing, inside and out spotless, case cover, interior cvt, everything. I can't express this enough!
Install new rollers and a new belt. With the variator and clutch system brought back to a like new condition it will be a whole lot easier to tell what is malfunctioning. It's very difficult to tell when the pieces already show wear.

[supertoast92]

Well, thanks for the suggestions everyone! We ended up having to get new rollers for the driver pulley, they were in worse shape than we thought. We did run it several times on jackstands and the CVT seemed to be operating just fine, with the belt running the entire range. We ordered a new variator, also, because we had no luck rubbing residue off the plates. Also we had to replace the nut for the driven pulley, it was wobbling when we were trying to put the CVT back together. I think the head was bent.

So, hopefully, with the CVT basically rebuilt once the 2nd batch of parts arrive, the Helix will be running as good as new. If not, we're thinking of trading it for a Carbide.

[supertoast92]

Well, just to update everyone on the status of the cart: We completely rebuilt the CVT last night with all the new parts (new driver + driven pulleys, belt). We put it back together, seems to be working fine. I ran it hard for a good half hour, going through the yard and what not, and it seems to be working fine again. I can't believe how much acceleration we had lost with the wearing parts! I was having quite the time with the pickup speed

So hopefully it's fixed. I need to drive it for a few more hours to confirm the testing, as that's about as long as the belts lasted before they began slipping. I tell you, that belt was extremely difficult to get onto those new pulleys. I wonder if it was the clutch spring went bad before. That's replaced now with a new clutch ASM so hopefully she'll be good to go.

But, I think we're beginning to have an old problem again with the starter sticking. Half the time I turn the key, I can just hear the starter relay click and nothing else. I let off the key, wait a few seconds and sometimes it'll work. It might be time for a new battery, as the charger wasn't showing much of any Amp drawage when I hooked it up. Last time we ended up replacing the whole starter, was quite a hassle with the electrical box blocking it. But the new starter worked like a champ.

So, hopefully it'll be running okay now. It's had so much downtime the past year

[SYCARMS]

The last problem you spoke of sounds like either a ignition switch or a solenoid. Try spraying some WD40 in thwe switch. The switches are not waterproof and sometimes will get corrosion on the contacts. TOM