The Ultimate Go-Kart Belt Size Chart

Welcome to the ultimate go-kart belt size chart, also known as a go-kart drive belt size chart. This chart features all Comet torque converter belt sizes that are most common for go-karts. This size chart also includes important belt size information, such as model, type, part number, pulley compatibility, outer circumference and top width. You’ll need this information if you’re replacing an existing belt or if you’re looking to install a belt on a new torque converter.

Go-Kart Torque Converter Belt Size Chart

BrandModelTypePart Number6" Pulley7" Pulley7.5" Pulley8.5" PulleyOuter Circum.Top Width
Comet20 SeriesSymmetric203578A6 5/8" to 6 11/16"---27.36"3/4"
Comet20 SeriesSymmetric203579A7 1/8" to 7 3/16"6 1/4" to 6 5/16"--28.32"3/4"
Comet20 SeriesSymmetric203580A7 9/16" to 7 5/8"6 13/16" to 6 7/8"--29.28"3/4"
Comet20 SeriesSymmetric203581A8 3/16" to 8 1/4"7 5/16" to 7 3/8"--30.25"3/4"
Comet20 SeriesSymmetric203582A8 11/16" to 8 3/4"7 3/4" to 7 13/16"--31.23"3/4"
Comet20 SeriesSymmetric203583A9 3/16" to 9 1/4"8 5/16" to 8 3/8"--32.2"3/4"
Comet20 SeriesSymmetric203584A9 5/8" to 9 11/16"8 3/4" to 8 13/16"--33.18"3/4"
Comet20 SeriesSymmetric203585A9 15/16" to 10"9 3/16" to 9 1/4"--33.78"3/4"
Comet20 SeriesSymmetric203586A10 3/4" to 10 13/16"9 13/16" to 9 7/8"--35.14"3/4"
Comet20 SeriesSymmetric203587A11 11/16" to 11 3/4"10 15/16" to 11"--37.11"3/4"
Comet20 SeriesSymmetric203588A13 1/16" to 13 1/8"12 1/8" to 12 3/16"--39.77"3/4"
Comet30 SeriesAsymmetric203589A7" or less---27.36"3/4"
Comet30 SeriesAsymmetric203590A7 1/8" to 7 3/16"6 1/4" to 6 5/16"--28.32"3/4"
Comet30 SeriesAsymmetric203591A7 9/16" to 7 5/8"6 13/16" to 6 7/8"--29.28"3/4"
Comet30 SeriesAsymmetric203592A8 3/16" to 8 1/4"7 5/16" to 7 3/8"--30.25"3/4"
Comet30 SeriesAsymmetric203593A8 11/16" to 8 3/4"7 3/4" to 7 13/16"--31.23"3/4"
Comet30 SeriesAsymmetric203594A9 3/16" to 9 1/4"8 5/16" to 8 3/8"--32.2"3/4"
Comet30 SeriesAsymmetric203595A9 5/8" to 9 11/16"8 3/4" to 8 13/16"--33.18"3/4"
Comet30 SeriesAsymmetric203596A9 15/16" to 10"9 3/16" to 9 1/4"--33.78"3/4"
Comet30 SeriesAsymmetric203597A10 3/4" to 10 13/16"9 13/16" to 9 7/8"--35.14"3/4"
Comet30 SeriesAsymmetric203598A11 11/16" to 11 3/4"10 15/16" to 11"--37.11"3/4"
Comet30 SeriesAsymmetric203599A13 1/16" to 13 1/8"12 1/8" to 12 3/16"--39.77"3/4"
Comet40 & 44 SeriesSymmetric203783A--7 1/4"-31.95"7/8"
Comet40 & 44 SeriesSymmetric203784A--7 7/8"-32.9"7/8"
Comet40 & 44 SeriesSymmetric203785A--8 3/16"-33.87"7/8"
Comet40 & 44 SeriesSymmetric203786A--8 5/8"7 5/8"34.83"7/8"
Comet40 & 44 SeriesSymmetric203787A--9 3/8"8 3/16"35.8"7/8"
Comet40 & 44 SeriesSymmetric203788A--9 3/4"8 11/16"36.78"7/8"
Comet40 & 44 SeriesSymmetric203792A--10 1/8"9 3/16"37.75"7/8"
Comet40 & 44 SeriesSymmetric203789A--10 1/2"9 5/8"38.65"7/8"
Comet40 & 44 SeriesSymmetric203790A--11 1/2"10 9/16"40.5"7/8"
Comet40 & 44 SeriesSymmetric203791A--12 5/8"11 11/16"42.66"7/8"
Comet40 & 44 SeriesSymmetric204331A--13 3/4"12 5/8"44.53"7/8"
Comet40 & 44 SeriesSymmetric213295A--14 11/32"13 13/32"45.38"7/8"
Comet40 & 44 SeriesSymmetric213165A--15 3/16"14 7/32"47.5"7/8"
Comet500 SeriesSymmetric300619A--7"-30.4"0.92"
Comet500 SeriesSymmetric300620A--8"-32.29"0.92"
Comet500 SeriesSymmetric300621A--8 1/2"7 1/2"33.24"0.92"
Comet500 SeriesSymmetric300622A--9 1/2"8 1/2"35.16"0.92"
Comet500 SeriesSymmetric300623A--10"9"36.13"0.92"
Comet500 SeriesSymmetric300668A--15"14"45.91"0.92"
CometTC88 SeriesSymmetric200419A6 5/8" to 6 11/16"---27.36"5/8"
CometTC88 SeriesSymmetric200420A7 1/8" to 7 3/16"6 1/4" TO 6 5/16"--28.32"5/8"
CometTC88 SeriesSymmetric200421A7 9/16" to 7 5/8"6 13/16" to 6 7/8"--29.28"5/8"
CometTC88 SeriesSymmetric200422A8 3/16" to 8 1/4"7 5/16" to 7 3/8"--30.25"5/8"
CometTC88 SeriesSymmetric200423A8 11/16" to 8 3/4"7 3/4" to 7 13/16"--31.23"5/8"
CometCAT99 SeriesAsymmetric200393A7" or less---27.375"5/8"
CometCAT99 SeriesAsymmetric200394A7 1/8" to 7 3/16"6 1/4" to 6 5/16"--28.32"5/8"
CometCAT99 SeriesAsymmetric200395A7 9/16" to 7 5/8"6 13/16" to 6 7/8"--29.28"5/8"
CometCAT99 SeriesAsymmetric200396A8 3/16" to 8 1/4"7 5/16" to 7 3/8"--30.25"5/8"
CometCAT99 SeriesAsymmetric200398A9 3/16" to 9 1/4"8 5/16" to 8 3/8"--32.23"5/8"

How to Read the Belt Size Chart

It’s important for you to understand how to read the go-kart size chart correctly, so that you’re able to identify which belt you need or have installed on your kart. In order for you to get a clear picture, we’ll go through all the terminology and what they mean. Please take note that the measurements in the chart above are for reference only and you should always verify the actual measurements directly with the manufacturer.


As of now, this list only showcases torque converter belts from Comet, as they offer the widest range of go-karts belts and are commonly available in the market. As this is a live list, I’ll be adding more brands over time. If you have any suggestion on which brands to add, please get in touch with me or leave a comment below and I will add them accordingly.


The model name indicates a series of a particular brand. In the list above, I’ve added the most common models from the Comet brand. You’ll find the 20 Series, 30 Series, 40 & 44 Series, 500 Series, TC88 Series and the CAT99 Series. Each series contains different variants and the series is used as a grouping.

The part number indicates the different variants of the series. For example, the Comet 20 Series go-kart belt has 11 different belts, each with its respective dimensions for different torque converters.


Go-kart belts come in different types, symmetric and asymmetric. This refers to the cross section design of the torque converter belt. For example, if you look at the go-kart belt size chart above and see a belt that has a asymmetric design, it means that from a cross sectional view, the outer borders are angled differently. 

Symmetric go-kart belts have a top angle of 15 degree on both sides. An asymmetric belt has an 18 degree angle on one side and a 2.5 degree angle on the other. The belt type depends on your torque converter model and design. For further reference, see the illustration below.

  • 20 Series: Symmetric
  • 30 Series: Asymmetric
  • 40 & 44 Series: Symmetric
  • 500 Series: Symmetric
  • TC88 Series: Symmetric
  • CAT99 Series: Asymmetric
go kart belts

Part Number

Each belt model or series has a subset of belts with different dimensions. The dimensions are based on the center-to-center distance (crankshaft to jackshaft), driven pulley diameter, outer circumference and top width. You can think of the part number as an SKU (Stock-Keeping Unit) number. So if you’re looking for a particular belt, you can simply refer to the part number for reference. 

For example, the belt with the part number 203578A refers to a Comet 20 Series go-kart belt for a 6” rear pulley diameter, a center-to-center distance between 6 5/8-inches to 6 11/16-inches, an outer circumference of 27-inches and a top width of 3/4-inches. The part number is also printed on the outside of the belt in white color.

Pulley Diameter

The pulley diameter refers to the diameter of the driven pulley that is attached to the jackshaft and is typically larger than the driver pulley. Comet go-kart belts support driving pulley diameters of 6”, 7”, 7.5” and 8.5”.

Outer Circumference

The outer circumference (shortened to “Outer Cirum.” In the go-kart belt size chart) refers to the circumference of the torque converter belt. The circumference is measured from the outside of the belt, not the inside. As you can see in the belt size chart, Comet offers belts with an outer circumference size from as short as 22″ to as long as about 45″+.

Top Width

The top width refers to the width of the go-kart belt on the top side. The reason why the width of a belt needs to be measured from the top is because from a cross sectional point of view, the top and the bottom are unevenly wide. 

This is due to the angles on the asymmetric and symmetric belts. Therefore, all width references that are made to go-kart belts always refer to the widest area, which is the top of the belt.


I’ve created a separate guide on how to measure a go-kart belt. This guide is easy to understand and contains a step by step process that you can easily follow. 


I hope that the go-kart belt size chart was useful to you. Please feel free to get in touch if you have any questions or suggestions on which go-kart belt brands and models to add.

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About Gerrit

Owner, Researcher, Writer & Editor at

Hi, I'm Gerrit. I have been racing go-karts competitively and recreationally for the past 20 years. Apart from actively growing local karting communities, I run GoKartGuide and write comprehensive articles, guides & reviews about go-kart racing. I race, build, mod, & discuss go-karts whenever I find the time. Thanks for stopping by and enjoy the read!

39 thoughts on “The Ultimate Go-Kart Belt Size Chart”

  1. I have 7” pulley with 9 1/2” c2c! 5/8 top! Old old old 3 wheeler! Sperry rand! Please help with belt! Thanks

    • Hi Rick!

      Thanks for writing in!
      None of the Comet belts would fit for 5/8 top width belt.

      Two options I can think of:
      Are you able to identify the old drive belt make/model?
      Or are you able to move the driver/driven pulley closer?

      • The belt on it is a newer belt that does not work! It would be a major alteration to the chassis or body to make it closer! I was really hoping to keep it as stock as possible! It was purchased in the 60’s by my great grand parents!

        • Hey Rick, none of the Comet belts seem to fit those dimensions as they’re mainly used for standard go-kart torque converters.
          I’ve tried to do some research as well but it seems that these dimensions are not easy to find. Perhaps they are too outdated.

          The CAT99 series from Comet is the right width but meant for shorter c2c distances.

    • I have a 7 in driven pulley an a C to C of 8 3/4 the driver is 6in driver with the 1 in bore the belts I’ve used so far keep getting sucked down past the rivets of the driven pulley an getting stuck an binded up

  2. Where can I find the belt for 24.5 circumference . As by your chart: (203589A 7″ or less – – – 24.5″ 3/4″) I can only find in 27 or larger in circumference. 27 is to loose and It slides over the pulleys.

    • Hi Kelly,

      Do you have the model of the torque converter?
      I can take a look for a compatible belt.
      Or you can pass me your center to center distance.

  3. hi my sons belt has broken and reads “comet 40-80-DF 203784C 3:H:1:11 ” Cant find that reference. Can you help me with a reference please? Thank you and regards Glen

    • Hi Glen,

      Thanks for writing! The reference for that is 203784 and 203784A (Comet 40).
      Just make sure that you also compare the measurements on the product pages before you buy anything to be safe!

      Alternatively, measure center-to-center distance and both pulley diameters to find an alternative.

  4. I have a tecumseh motor. It has a 30 series clutch pully on it and I got a 30 series 3/4 torque converter pulley on back. The belt I had is to big now and its 8485 size. Or its size pp- 203597 witch is a asymmetra. From bolt to bolt on the pulleys are 10in. Can u please help me get the size I need. Thank you

    • Hey Justin,

      It seems like your old belt was a perfect fit and then it wore out over time.
      I would always suggest getting a direct replacement: 203597A (asymmetrical).
      You should also maintain the belt regularly and check for wear.

      Alternatively, if the aold belt also doesn’t fit, ensure that you take into account the pulley diameters, as well.

  5. I have a comet series 40 setup. So 7.5″ driven pulley, but the center to center is 18.5″. I can’t find any chart with a belt that long. Can you help?

    • Hey Scott,

      That’s strange, I’ve never seen that long of a center-to-center distance before. Is that a custom setup, or installed stock?

  6. I have a driver
    4-3/4”driven 6” and c to c 6-5/8. Asymmetrical I don’t see a chart to look for measurements. Can you confirm witch belt I need thanks

    • Hi Brad,

      Seems like an unconventional torque converter size. Do you have a belt part number or torque converter model name/number?

  7. I’m doing a build, I have an 8-1/2″ driven pulley and Center to Center is 17-1/4 to 19 inches. Engine isn’t bolted down yet so I have some wiggle room. Do you have a belt that would fit?

    • Hi Isaac,

      Seems like quite a large center to center. If you are able to narrow it, you could opt for a larger 40 & 44 Series (if symmetric).

  8. Good evening. Have an old Manco Dingo 2 seater with a Comet torque converter. Can’t seem to figure out which belt it uses. C2C I’m getting 7 15/16” on a 7” pulley.

    • Hi Cole,

      Based on your measurements it should be a Comet 20 Series 203581A or 203582A.
      Best to check in the owner’s manual or by your model name.

  9. Your guide neglects the Comet 780 series.

    I have a 780 series. The driven is almost 11″ in diameter, and I currently have c2c of 11.5″, though I can modify the setup to slightly shorten the c2c.

    Any help would be great!

  10. I have a pocket bike with center to center of pulleys 5″1/4″ diameter of both pulleys are 3″1/2″ that drives a #35 chainto rear wheel I can’t seem to find any kind of I.d. # on housing . Pocket bike was on a pallet of misc things I bought at auction many years ago i just need a belt. Engine is 49cc

  11. I have a 70 72 model Muskin’s Dune Cat Dune buggy and the driven pulley is around 6 1/2″ and the c2c is around 9 7/8″ what belt do I need?

  12. So my biggest question I have is I build mini bikes and I’m using your 30 series torque converter 3/4 shaft and I’m trying to find out if anybody could tell me which would be the better driver pulley a 6 or 7 in can anybody give me a little advice on which one I have to stick with please any help would be useful

  13. My measurements are center to center 9 an 5/8in an driven pulley is 7.5 30 series, 3/4 width, what belt do i need

  14. I have a 2020 cheetah go kart with a 208cc motor and I think I have the wrong belt because they keep snapping. Could u help me find the right size?

  15. Hey Gerrit- I have a Blast LED 30 series torque converter. The belt it came with is horrible. It says the dimensions are ‎14 x 8 x 2 inches, which doesn’t sound correct. What belt that you sell would fit. Thx!

    • Hey Rob, thanks for getting in touch.
      I don’t sell any belts, I’ve only compiled some useful information for reference.
      Have you tried to search for a suitable one on Amazon? They have a good selection!

  16. I have a memory Motorsports go kart with a 420cc the clutch and the converter is not attached to the motor it is on two separate axles which on the other side of the axle that the the clutch is on the other end runs the chain where do I find a belt for a Mercury Motorsports go kart with a 420

  17. VERY useful explanation. Thank you!
    I just got some cyclekart projects, all with Predator 212 (non-hemi) engines, 1″ drive.
    One engine is stock (6.5 hp), and I’m sure the Chinese torque converters (Each engine has one) will work okay with that. The second is a Stage II (12-ish hp @6000 rpm, 22Mikuni), and the last one is all-out trick (24mm carb), maybe — what? — 20hp @8000+rpm. All are currently set up with #35 chain sprockets.
    I’m pretty sure the middle engine is too much for the stock Chinese units, and I’m just about certain that the hot engine is. I’d like some American quality spinning 10″ behind my head. Do I need to go to a 40 series?
    What clutch/torque converter do you recommend?

  18. I’ve got a buggy fitted with a comet 94c duster clutch and a 90d driven clutch with clutch shaft centres of 15” would anybody be able to point me in the right direction of belt sizes as I can’t for the life of me figure it out

  19. i have a ken-bar high performance streaker fun kart pace maker. pullys from center to center is 13 in. pullys sizes are aproximatly 5 in. and 61/2 in. asymmetric. serial # 155531 model # is painted over. i do not know what series it is. can you tell me the belt # and size ? thank you.


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