CVT overheating By motley (Read 3,513 times)

[motley]

This actually happened three weeks ago but I ignored it as I didn't intend on riding the scooter for some time. I'm going to attempt to do an exact rundown.

Originally the rear wheel locked up and I almost went down with the bike. I couldn't even push it. I found out the belt snapped inside of the clutch.

One hundred percent cleaned the clutch and nothing seemed faulty other than being stock..

The rear wheel was fully examined, it appears one of the brake shoes became faulty, after cleaning that area it seemed to be fine.

I cleaned the entire CVT area. Nothing oil based. Nothing abrasive either.

I replaced the varriator, I thought I had broke it but I didn't, when I broke down it ended up getting stuck in high gear. Never seen such a thing in my life.

Well after a new bbk and a strong look over I knew the bike was ready for testing. Drove around 25 miles just fine.

Day two: after 17 miles I heard a squash sound. I assumed the belt stretched due to heat. After a partial pull over I managed to find somewhere to waste time while that area cooled. On start up I could tell the rollers had flat spots at that point. You could feel the rumble on the handle bars in low gear. But managed to put slowly to work..

I knew regardless I was breaking down. And I did..

It sounded like the varriator flew off the shaft. I swore I heard the rollers smack inside but I was way off.

After inspecting, the CVT area is 10 times dirtier than before, as well the clutch. The belt is oddly still on but shredded. The varriator fan is melted really bad..

Other than that the bike still runs.

I know this is possibly an air flow issue..

But what could honestly possibly be the culprit? Maybe gear oil levels? Brake shoes rubbing without me knowing transferring heat to the CVT?

I'm honestly lost right now..

Sorry for the long post I tried explaining everything..

[motley]

I was off about the rollers.

But oddly almost all of the belt was intact except where the clutch is. Only a string holding that area together. Even with new rollers the bike has the rumble to the handle bars.

I'm thinking the clutch is the culprit to mass heat exchange.

But I'm no expert..

[cyborg]

I'd be looking at the final drive area,,,get the back tire off the ground and pull off the clutch and then check the rear shaft,,the bearings might possibly be on their way out,,,check for roughness when you rotate the shaft also check for play in the bearings

[motley]

Thank you for the pointer! I'll check it out when I get off.

[motley]

Finally got off work.

I'm going to at least take the muffler off so I can gain access to the tire. I'll attempt to take off the rear wheel, I'm just over exhausted.

But originally the rear clutch shaft would stick. But it fixed once I took apart the brake shoes and reinstalled them.

On topic, I'll just replace the bearing. If there's anything else I should replace while I'm taking that area off could you let me know please?

Also is that bearing in the gear oil area? Sorry I don't mean to sound dumb. Just trying to see what to expect. I might upgrade the gear set while I'm at it.

[czmdiver]

You shouldn't have to take anything apart
Raise the rear wheel off the ground and with the belt Off spin the rear wheel. you do have gear lube in the gear case correct?
If ya have a munched bearing you will be able to tell juts by spinning the wheel less the belt.and that won't cause yu to break belts.
What brand of belt are you using?
Pictures would really be a big help..


Here is what inside

[motley]

Hey czmdiver.

I attempted to work on it but my tools went missing. But yesterday I did that after dissembling and resembling the brake shoes. There's a bit of a snag if I tighten the brakes sadly a little.

If you tighten the brakes well it's push squeak, push squeak. Repeated sequence after every 360 turn to the wheel. During the squeaks the rear wheel locks up a little, pretty positive it's the brake shoes doing that.

I have considered getting a shorter drive shaft for the wheel any who, plus changing out the gear set to a higher ratio.

As for gear oil. I did the entire lock thread method in the drain bolt. I have always inspected that area for any leaks plus I typically feel the case right there. The motor is pretty new. That I'm aware of miles wise it only has 5,000 on my part.

Belt brands are Gates. And a few cayco. Haven't found any off brands as of yet.

I ordered a new clutch. Rebuilt a used varriator, like new.

Atm I'm looking into rebuilding the rear just so I know everything is covered.

Do I need a hydrologic press like the internet is saying?

Also does it matter if I use synthetic gear oil? I'd like to go with royal purple.

[motley]

I strongly inspected a lot on the bike but I sadly ran out of light..

One: bike needs new brake shoes, without the rear wheel on the bike seems to no longer rumble. I could be wrong. But I definitely didn't find it trying to rumble in low gear. There was a shake to the bike but I blame the bbk causing more top end.

Two: long case engine with brake shoes for 12 - 13 inch rims, but using a 10 inch wheel. I measured my original from the old motor and the one I ordered is just slightly smaller than the one on the short case, "slightly".

The worst part is the part of the wheel where the brake shoes hit might be bent.. Or its a screw up with faulty brakes.

If I have time on Friday I'll be installing the rebuilt varriator, a brand new clutch. A brand new belt, yet new brake shoes that shouldn't rub.

If all of this does not fix my problem, I'll be doing measurements of the wheel just to see if it is bent. It's ten years old so who knows..

If my problem isn't fixed by then, I'll order a new bearing and pre dissemble the gear box to find out what's going on from there.

*I'm going to be looking for cheap hosing in the next few days to create something ingenious with the varriator vent. Dunno if it'll blow in. But it's worth a shot..

[czmdiver]

The Hub inside the Wheel for your Brake is Out of Round, that is why when you adjust the Brake it Drags in one part of the Rotation.
Many, Many many of them are Out of round from the Factory Brand new. its very common.
Mine was and I bought it and I bought another Wheel and Its Hub is Out of Round. you simply cannot adjust the brake up without them dragging .

[motley]

That makes a lot of sense. These wheels are aluminum alloy. Thanks for the definition, the wheel hub is beyond shinny and slick. So where the brake shoes. I think there was random seizing going on because of it, plus heat. I'm sure that heat transferred to the CVT area somehow.

I drained out the gear oil and replaced it with Lucas gear oil, 80w 90w.

I attached a clamp to the rear axle and tested the gears in many different rotations. I don't know if it was good luck from the new oil but it was much smoother. Yet the spin grew quicker overtime.

If there was a lack of oil there it should decrease heat.

I'm awaiting for my new clutch to come in as well brake shoes by tomorrow.

I need to invest in a method to change belts varriators etc from anywhere. Regardless if it ate a belt again I could make it home.

As for not being able to adjust the brakes without dragging kinda answers my question with the beyond slick hub. Yet the pads are practically gone. It just had to of been seizing slightly during rides causing crazy heat. Found black dust in the hub

[motley]

Replaced practically everything except anything gearbox related. But I did change out the gear oil. I was rather wasteful ensuring all of the oil moved to the bottom.

The entire bike moves with ease. There's no more rumble to the bike. Even with a bbk no vibration other than hearing the center stand squeak.

Everything seems to be checking out great, except for heat once again. The gear box is cool to the touch. But everything else transmission related is not..

Since I can't document temps, I'd guesstimate the CVT cover is between 197 - 280 F. I work in a kitchen so I'm pretty good with eyeballing temperatures.

Should I worry about these temperatures? I fear the belt stretching and busting.

Behind the CVT cover is also hot. I know the timing chain is ran in that area. But I'm not sure if there's something internal that could be inefficient causing heat.

I suppose my best bet is asking for a link for a good belt that can stand heat + stretching. As long as it's a number 723. Not worried about the width for performance at this point sadly..

If you happen to have any thoughts as to if there's something internal causing this please let me know as well if I should even be worried.

*what's a good idle time to test the belt to see if it'll snap? I don't mind breaking down during testing, but I want to keep it close to home.

[cyborg]

Heat is a major problem with cvt transmissions,,,the main reason I got rid of my Vespa et4,,,even a mild jaunt to the store a couple miles away the cvt cover would get so hot you couldn't touch it,,,you'd get a serious burn,,,and all that wasted power to generate that kind of heat means wasted go power,,,lots of members here and on other forums skelotonize their covers or get a kit to eliminate the cover altogether ,,,

[snaker]

Couple of points.
My GY6150 has a filter inserted in the CVT cover cooling intake snorkel.
That picks up a lot of dirt and plugs, causing a hotter CVT.
I don't know if all these machines have this filter but you may want to check.
Also if your considering modifying or replacing the CVT cover, first check to see if your rig use's a CVT cover support bearing for the gearbox input shaft.
You have to have at least enough cover to use the four rearmost mounting bolts to support the support bearing.

[motley]

I'm stuck at work and can't respond like I really want to sadly..

I want to ask a question that'll make you say .. Could someone cut open a hole inside of the CVT area so the chain could act as a fan?

It's a dumb but logical question..

[czmdiver]

Jun 16, 2018 11:41:25 GMT -6 motley said:

I'm stuck at work and can't respond like I really want to sadly..

I want to ask a question that'll make you say .. Could someone cut open a hole inside of the CVT area so the chain could act as a fan?

It's a dumb but logical question..

What Chain?