Cheap Chinese TC? / A lesson in rushing purchases.

[Squiddy202]

Hello,
Sorry it has been so long. Over the winter I got a ton of snow so that put all of my kart stuff on pause. I know I should have checked and tried to answer questions, but I didn't and I am sorry. I was looking to get a CVT. I want to get a decent belt but for the pulleys I need them as cheap as possible as I am yet to get a part time job. The issue is that the cheap stuff suddenly became less cheap with tariffs. Does anyone have recommendations? Will an AliExpress pulley shatter and become shrapnel?

 

[Thepartsguy]

I use 1” torque converters and got my whole cvt setup for $25 around Christmas time years ago. Just use a genuine belt.

 

[Squiddy202]

I use 1” torque converters and got my whole cvt setup for $25 around Christmas time years ago. Just use a genuine belt.
View attachment 160037

What dimension is 1"? I am looking at Ebay and a lot of them list a driven size and a drive bore but not a drive diameter. Does the diameter of the drive pulley not really matter? I don't doubt you got it cheap, but without going into politics, the recent tariffs have raised prices from where I would assume you got it. Thanks though!

 

[Whitetrashrocker]

What is the size of your outputshaft on the engine?

3/4 is the common size for 212s. Then you can use a 30 series and thay are pretty cheap from the jungle store.

If you have a 1' shaft then you need to jump up to a 40 series. They can be a bit more but the knock off are still pretty cheap.

 

[Squiddy202]

What is the size of your outputshaft on the engine?

3/4 is the common size for 212s. Then you can use a 30 series and thay are pretty cheap from the jungle store.

If you have a 1' shaft then you need to jump up to a 40 series. They can be a bit more but the knock off are still pretty cheap.

I'm almost positive it is 3/4, however, is 30 series the measure of the driven or is that something else? I am trying to be sure I have the right ebay find before dumping money. I can find the bore, and driven size, but not the drive pulley size, is the series the drive size?

 

[Whitetrashrocker]

They are a matched set kinda.
A 30 series is an asymmetrical belt. The driven unit comes in 6" or 7" diameter.
The 40 series uses a symmetrical belt.
Parts are not interchangeable.

Do you have a jackshaft or do you need the back plate.

I have 2 of these now and no issues.

 

[Squiddy202]

They are a matched set kinda.
A 30 series is an asymmetrical belt. The driven unit comes in 6" or 7" diameter.
The 40 series uses a symmetrical belt.
Parts are not interchangeable.

Do you have a jackshaft or do you need the back plate.

I have 2 of these now and no issues.

View attachment 160040

I do have a jackshaft. Is there a pro/con to a 20/30/40 series? I have seen that the standard is 30, but does the symmetric/asymmetric really matter?

Edit:
I have an off-road cart with big tires. It has ~7 hp. The Google answers talk about heavier duty, but don't know what that is considered.

 

[Whitetrashrocker]

Torque Converters (CVT’s) | Comet Clutches

 

[Squiddy202]

Torque Converters (CVT’s) | Comet Clutches

Fair, I gotta go to Google first. My bad man.

 

[Hellion]

Fair, I gotta go to Google first. My bad man.

Phooey! Ask the forum (you already did) or do a forum search. We've got a handful of members here who are well versed on the topic and usually happy to help PLUS a giant database covering the same questions (there's nothing new under the sun). Give folks here at least 24 hours to answer as people come and go.

Anyway, the TCs are all horsepower rated, or rated for different uses/different engines basically.

Some have symmetrical V belts, some use an asymmetrical belt, for example.

 

[Hellion]

Will an AliExpress pulley shatter and become shrapnel?

Aliexpress TC parts and ebay/Amazon TC parts are probably all made in the same factory. But this forum always needs guinea pigs for product testing, assessment and review.

Just recently had someone buy the Amazon $25 10,000 RPM 212cc flywheel.

 

[panchothedog]

Squiddy, if your 7 hp. engine is a modern OHV (not a flathead) it most likely has a 3/4" output shaft. Most ALL 30 series torque converters ( there are exceptions )
the driver is a 3/4" bore, and the driven ( the bigger one in the back ) are 5/8" bore. Don't worry about the overall diameter. They are matched to work as a pair.
NOTHING is interchangeable between a 20 - 30 - or 40 series. Even with having a jack shaft already, you can probably buy a complete plate system cheaper than the 2 clutches individually. The Amazon $60 ones shown by WTR in post # 6 work very well. I have several of them, some well over 10 years old.

 

[Squiddy202]

Squiddy, if your 7 hp. engine is a modern OHV (not a flathead) it most likely has a 3/4" output shaft. Most ALL 30 series torque converters ( there are exceptions )
the driver is a 3/4" bore, and the driven ( the bigger one in the back ) are 5/8" bore. Don't worry about the overall diameter. They are matched to work as a pair.
NOTHING is interchangeable between a 20 - 30 - or 40 series. Even with having a jack shaft already, you can probably buy a complete plate system cheaper than the 2 clutches individually. The Amazon $60 ones shown by WTR in post # 6 work very well. I have several of them, some well over 10 years

Quite frankly I found a cheap eBay set and was going to buy a new belt, how do I know the plate set will fit my engine/kart?

Edit:
The set I was looking at had no plate and I would measure the pulleys once they are on and buy a belt.

Edit 2:
I have a jackshaft so I don’t need the sprocket connected to the driven pulley.

Edit 3:
My engine is this just not on the cart. Someone mentioned holes for mounting a plate, are those the ones right around the shaft? I am at school so I can’t check for mounts on the jackshaft.

 

[Squiddy202]

Just recently had someone buy the Amazon $25 10,000 RPM 212cc flywheel.

Living life on the edge!

 

[Squiddy202]

Phooey! Ask the forum (you already did) or do a forum search. We got several eggspurts such as Denny, Panchothedog, WTR and Jim D from Max-Torque (who manufactures their own CVTs and clutches) who are well versed on the topic. Give folks here at least 24 hours to answer as people come and go.

Yeah I thought the lack of context was trying to show how easy it was and that I should have checked google first. Not throwing shade at WTR. I over-analyze things sometimes.

 

[Hellion]

Quite frankly I found a cheap eBay set and was going to buy a new belt, how do I know the plate set will fit my engine/kart?

Edit:
The set I was looking at had no plate and I would measure the pulleys once they are on and buy a belt.

Edit 2:
I have a jackshaft so I don’t need the sprocket connected to the driven pulley.

Edit 3:
My engine is this just not on the cart. Someone mentioned holes for mounting a plate, are those the ones right around the shaft? I am at school so I can’t check for mounts on the jackshaft.

For Edit 3, yes. The holes around the PTO/crankshaft on the engine block are usually tapped (threaded) for mounting up a TC backing plate. You can also add a clutch cover there and on some of the Doodlebug, Coleman and Warrior minibikes, a special jackshaft assembly was attached there at the factory.

 

[Squiddy202]

For Edit 3, yes. The holes around the PTO/crankshaft on the engine block are usually tapped (threaded) for mounting up a TC backing plate. You can also add a clutch cover there and on some of the Doodlebug, Coleman and Warrior minibikes, a special jackshaft assembly was attached there at the factory.

So even if my engine has the holes, how do I find the right backing plate? It seems like a good thing to have to protect the exposed driven components. It looks almost like the plate is for minibikes? I have a jackshaft. Do I mount the driven pulley straight to it? The listings have very little clarity. Keep in mind I have a Murray explorer. I can't get pics from a school computer, but check my CVT vs Centrifugal Clutch thread if you need them.

 

[panchothedog]

The ones like shown in post # 6 include the backing plate. Plus a useable ( not top quality ) belt. If the plate system doesn't fit on your kart, you still have the driver and driven clutches. The parts you need. The picture of your engine shows the 4 holes around the shaft onto which the plate is bolted.

 

[Squiddy202]

The ones like shown in post # 6 include the backing plate. Plus a useable ( not top quality ) belt. If the plate system doesn't fit on your kart, you still have the driver and driven clutches. The parts you need. The picture of your engine shows the 4 holes around the shaft onto which the plate is bolted.

Do the plates work with jackshaft though?

 

[Thepartsguy]

Do the plates work with jackshaft though?

Photos stolen from musti1 YouTube channel of his rupp mini bike.

He installs the driver pulley onto the crank. The driven pulley onto one side of the jackshaft.

The other side of the jack shaft runs a 12t sprocket back to the 60t wheel sprocket.