How to Measure a Go-Kart Belt for Torque Converters
You may be familiar with torque converters on go-karts. Compared to a sprocket and a roller chain, a torque converter has two pulleys and a drive belt. As drive belts can wear over time you may need to replace your belt with a new one. In this case you need to ensure to get a go-kart belt that is the right size, in order to avoid damaging the torque converter and the belt itself.
In this guide, I’ll be teaching you how to measure a go-kart belt and some of the things that you need to look out for. In short, in order to measure your go-kart belt you need to know the belt type, the torque converter pulley diameter and the center distance between both pulleys. If that doesn’t ring a bell, don’t worry! I’ll be going in-depth on each of these topics, so that you can follow them step by step. Without further ado, let’s jump right in.
Measuring a Go-Kart Belt
When it comes to measuring go-kart belts, you’ll first need to measure a few key things on your torque converter. This will reveal what type and size of go-kart belt you need for your go-kart setup. You can follow the 4 easy steps below, which will guide you through the entire process.
Step 1 - Determine Belt Type
The first thing that you’ll need to do is to identify which type of drive belt you need for your torque converter. When it comes to go-kart belts, there are two types. On the one hand, you have symmetrical belts, and on the other hand you have asymmetrical belts. The type of belt that you require for your go-kart depends on the type of torque converter you have.
If you look at the cross section of a belt, symmetrical drive belts are evenly angled at 15 degrees. An asymmetrical belt would have an angle of 18.5 degrees on one side and 2.5 degrees on the other. If you look at the illustration below, you can see the cross section of the two belt types. You can easily spot the type of belt by looking at each side of the go-kart belt.
If you’re looking for a go-kart belt for your torque converter and are unsure which type is required, you should look at the pulleys. Each pulley is made of two sides. If both of the pulley components are equally angled then you’ll require a symmetrical belt. If only one side seems to be angled and the other seems flat, then you’ll need an asymmetrical belt.
Step 2 - Measure Driven Pulley Diameter
The next measurement you’ll need is the diameter of the driven pulley. A torque converter has two pulleys. The pulley that is attached to the crankshaft is called the driver pulley, as it drives the belt through the rotation of the crankshaft.
The other pulley that is on the opposite end of the torque converter is called the driven pulley, as it’s driven by the belt. This pulley is connected to the jackshaft. You will need to measure the diameter of the driven pulley, as you will need the diameter in order to establish which belt size you require.
Measuring the go-kart driven pulley diameter is very easy and straightforward. Simply take a measuring tape and hold it against the outer plate of the pulley. Measure from one side of the plate to the opposite side. If you’re running a standard torque converter the diameter will either be 6-inches, 7-inches, 7.5-inches or 8.5-inches.
Step 3 - Measure Center Distance
The third measurement you’ll need in order to measure the go-kart belt size is the distance between the driver and the driven pulley. This distance is also known as the center distance. This distance is measured from the center of the crankshaft to the center of the jackshaft.
Measuring the center distance is very easy, simply hold a measuring tape against the center of the drive pulley to the center of the driven pulley. You don’t need to remove the torque converter or the plates for this. You can easily spot the center point from the outside. For easy reference, the center point of each pulley is the crankshaft and the jackshaft.
Step 4 - Check Measurement Against the Belt Size Chart
Now that you’ve identified the belt type, driven pulley diameter, and center distance you can easily determine which belt size you need for your go-kart torque converter. Head over to the go-kart belt size chart that I created. I suggest that you keep the belt chart open in a separate window and continue reading, as I will now teach you how to check for the right belt size.
Let’s work with the follow example:
- Type: Symmetric
- Driven Pulley Diameter: 7”
- Center Distance: 9 1/4″
In our example we have established that we require a symmetrical belt, the driven pulley diameter is 7-inches and the center distance is 9 1/4-inches (9.25”). Now, take a look at the chart and match those dimensions against the correct belt size.
Firstly, check all the symmetric belts that support a 7-inch pulley. That will be a Comet 20, Series, 30 Series and the TC88 Series. Now, check in the Pulley 7” column for a center distance of 9 1/4-inches. This should lead you to the belt Comet 20 Series with the part number 203583A. This go-kart belt has an outer diameter of 32.2-inches and a top width of 3/4-inches. Congratulations, that’s it! It’s that simple.
Frequently Asked Questions on Go-Kart Belts
Below are some of the most common questions that I’ve been asked about go-kart belts. If you have more questions, feel free to post them in the comment section below or reach out to me and I will have them added to the list.
What are the Available Comet Belts Series and Sizes
There are a few go-kart belt manufacturers, but the most common brand is Comet. If you’re buying a go-kart belt you’ll most commonly see them refer to the Comet equivalent so that you can always ensure that you’ve got the right size.
Below is a quick overview of what belt types and sizes there are for the Comet brand. I highly recommend that you check out the full go-kart belt size chart for a complete overview.
- 20 Series (Symmetric)
- 30 Series (Asymmetric)
- 40 Series (Symmetric)
- 44 Series (Symmetric)
- 500 Series (Symmetric)
- TC88 (Symmetric)
- CAT99 (Asymmetric)
How Tight Should Go-Kart Belt Be?
When it comes to the fitting, you should always stick with the manufacturer’s recommended sizing. If the center distance of your torque converter can’t be found on the belt chart, ensure that you get the one that is closest to the measurements. In the worst case, a looser belt is better than a belt that is too tight. However, try to ensure a perfect fit.
Before you start using a new go-kart belt for your torque converter, you should always check the belt tension. You can do this in the following way. Ensure that the belt is at the highest position on the driven pulley (driven flange). With the cover removed from the driver pulley, pull the belt past the crankshaft and ensure that there is a gap of about 1/8″ to 3/16″ between the crankshaft and the belt when it’s pulled.
You should ensure that the go-kart belt fits within this range. If the belt is too short or too long, it can lead to quicker wear or jerky acceleration. In this case you can either opt to install a fitting go-kart belt or you can mount the engine to different mounting holes of the torque converter, in order to ensure a good fit.
How to Fix a Go-Kart Belt That Keeps Jerking?
If you’re experiencing jerking when accelerating, there is a high chance that it may be because of your torque converter. You should immediately check the wear on your go-kart belt. If your belt is not lubricated properly, is too loose or is too worn, it may cause a jerky or even sluggish acceleration.
You should ensure that you maintain all your go-kart parts properly and this also includes the go-kart belt. Dust and sand can cause increased wear, which would require you to properly lubricate it.
How Long Does a Go-Kart Belt Last?
A go-kart drive belt can last from a few years to a few hours. Go-kart belts are usually made of a high-quality and sturdy rubber material that is made to last. However, you’ll only be able to make it last if you ensure proper maintenance and if the belt is the right size for your torque converter.
Burning your go-kart belt is a common occurrence if your belt is too tight or if the backplate is not straight. This causes increased friction and will heavily increase the wear on your go-kart belt. This reduces the belt’s lifespan and your torque converter. When this happens, your belt will turn hot. If that’s the case, it’s not uncommon to burn belts within a matter of hours.
If you’ve taken the time to ensure proper belt sizing and the torque converter is in proper condition, a go-kart drive belt can last for many years. That’s why it’s important that you understand how to measure a go-kart belt correctly. To ensure long lasting belts, make sure to maintain your torque converter and go-kart belt regularly. A belt lubricant will also help to increase its lifespan.