Updated TC belt destruction

[Daver]

Hi - I recently did a few mods to my go kart when the belt got stuck in the TC driver. I replaced the zinc weight assembly including the springs on the driver unit (connects to engine). One spring was bad and one of the bars was slightly bent. I thoroughly cleaned all the parts on wire wheel.

While I was at it I put in a exhaust header and muffler, an improved air filter (kn style), and a new jet (96 i think) into carb.

Kart seemed to run fine and maybe a bit faster. At low rpms when the belt starts to engage there is a bit of a squeaking sound but it goes away once the kart takes off.

After about an hour of riding the belt is noticeably thinner and the driver faces loOk pretty black and worn. Power is much lower and sometimes the kart doesn’t engage until I’m really down on th throttle.

Any idea what could cause the belt to start to breakdown after a basic TC upgrade like this?

 

[bob58o]

Any idea what could cause the belt to start to breakdown after a basic TC upgrade like this?

Chinese belts are not very good. Large Tires, Heavy Weight, and less-than ideal gear ratios will destroy belts at an accelerated rate.

 

[Whitetrashrocker]

Some pics really help in these situations.

I back tracked your other posts and I still didn't see what was needed in the few pics you did post.

How are the sheaves of both TC units? What does your belt look like?

The TC sheaves should be a polished smooth surface. If they are badly pitted and or rusty they will eat belts in a hurry.

Take your belt off and turn it inside out and press the back sides together and spin the belt to check the width along the whole length of it. Linear symmetry. If there are wide and narrow spots, it's toast.

There's tons of possibilities so let's start here..

 

[Daver]

Sorry pictures would help...the belt has been used for a while and no problems before I did the upgrades. As you can see in the pictures the driver faces the belt rides on look like they have some mort of heat damage. When I installed they were shiny and looked like new.

 

[anickode]

That rusty old driver sure isn't doing you any favors. Might as well hold a piece of sandpaper against the belt while it's spinning.

What is your gear ratio and tire size?

 

[Daver]

Yea it kinda looks rusty but it’s not. Yesterday it was perfectly shiny once I reinstalled everything. I took it off and it’s very smooth to the touch. Thing is none of this was a problem before I did the upgrades. So something changed when I replaced the zinc weights and reinstalled.

 

[bob58o]

Tell us the flipping gear ratio and tire size.

That is a lot of belt caked on the engine side cover.
Take the TC off,
Take it apart,
And show us?

The belt needs to be the correct length for the crankshaft to jackshaft spacing.

I think the the driver unit weights are supposed to go in a certain direction. The angles are different on each side of the weight pack. Not sure if that may be an issue or not.
At this point, I'd just turn them around and see.
I'm 94% sure it is the TC and not the engine upgrades.
If that don't help....

$30 fixes the problem most likely.
Plus a new belt from COMET
https://www.ebay.com/itm/TORQUE-CON.../282796398835?_trksid=p2349526.m4383.l4275.c1

 

[Daver]

Hi - I apologize but I’m not sure how to determine my gear ratio. My tires are 16” and I’m using what looks like a comet 30 cvt clone. Attached are more pictures but i think what it tells us is that something caused the belt to abrade the driver side. We ran the cart for an hour and it performed well. But perhaps at some speeds it was slipping for some reason and caused a lot of heat and belt wear.

The zinc weights with the 2 springs is what I replaced. I put it in with the flat side toward the engine and the angled side pointing away from the engine. Anyone know if that’s the right direction? I checked the comet docs and it kinda looked that way in the picture.

Thank you for the ebay link. That assembly on the go kart sites is a lot more so maybe it’s eaiser and time to get a new one. Although it’s really bugging me not to understand what causes this...

 

[Whitetrashrocker]

That rust bothers me.

 

[Daver]

Yea I hear you...but yesterday I had to really clean all over. I soaked everything but the weights (that was new) in citric acid solution and brushed all surface rust off. Then I took everything to th wirewheel on my grinder and got it nice and clean and shiny. Kart then ran for about an hour and eventually it looked like the pictures. So I think it’s more heat damage and belt residue than rust.

I’m going to throw in th towel and get a new TC driver from eBay. It’s probably time to get a new one anyway. Safe to assume all of these comet 30 clones are the same and will match my diven unit? If so then also safe to assume the same belt should work since the distance between the 2 shafts is the same...

 

[Whitetrashrocker]

If there's that much belt dust I'd get a new one.
Did you check it like I suggested?

 

[bob58o]

Hi - I apologize but I’m not sure how to determine my gear ratio.

Number of teeth on Rear Sprocket divided by number of teeth on little sprocket.


60 Teeth on rear and 10 Teeth on front is 60/10 = 6, expressed 6:1, (said 6 to 1)

60 Teeth on Rear and 12 Teeth on front is 60/12 = 5, expressed 5:1, (said 5 to 1)

---------- Post added at 11:11 PM ---------- Previous post was at 10:47 PM ----------


I think if it were me, I'd replace the entire driver unit for $30.
It looks beat up.



Copied an old post of mine....

I always forget the weight pack is also not symmetric and never take note of how it was. One side is flatter and the other side has more of an angle.

The outer shell (lubed) seems to have a more angled surface when compared to the inner shell’s flatter surface.

Makes sense that flat would go with flat and angled would go with angled, but I’m not 100%.

Last time I put one back together I had it backwards and had to switch it. Still don’t remember how it goes.

 

[Dingocat]

Number of teeth on Rear Sprocket divided by number of teeth on little sprocket.


60 Teeth on rear and 10 Teeth on front is 60/10 = 6, expressed 6:1, (said 6 to 1)

60 Teeth on Rear and 12 Teeth on front is 60/12


Copied an old post of mine....

I always forget the weight pack is also not symmetric and never take note of how it was. One side is flatter and the other side has more of an angle.

The outer shell (lubed) seems to have a more angled surface when compared to the inner shell’s flatter surface.

Makes sense that flat would go with flat and angled would go with angled, but I’m not 100%.

Last time I put one back together I had it backwards and had to switch it. Still don’t remember how it goes.

Angled side out

 

[Daver]

So I got the new TC today and added the spacer and then 1/2 driver that goes on the engine side. I then got a straightedge our and i'm a good 1/8" in front of the driven unit's back plate. I checked the series 30 manual and it doesn't explicitly say they need to be parallel - but it sure looks like they do in the pictures. On a few spots on the internet people talk about making sure they are parallel.

Perhaps this is what ate up my belt and destroyed my old TC?

Any idea what could have caused these to get so out of wack? Do I just grind down the spacer until they are perfectly aligned?

 

[anickode]

Yep, just thin down the spacer.

Parallel also does not mean perfectly aligned. Though the sheaves shoyluld be aligned, parallel is referring to the axes of the shafts. Making sure one isn't angled.