Go-Kart Clutch – The Ultimate Guide for 2021


go-kart clutch

A clutch is an essential component inside a go-kart and is partially responsible for the go-kart taking off and stopping properly. Clutches are not exclusive to go-karts. Other motorized vehicles, such as cars, have clutches. Fundamentally, the purpose of a clutch for all of these types of machinery is the same. 

A go-kart does not have a transmission, so the clutch has a different function than it would in a car. Instead of shifting gears, the clutch engages and disengages the engine. Stop and go are both two primary functions in a go-kart, but essential for making the go-kart run and ensuring its safety in stopping. 

There is a lot of technical information to be considered with go-kart clutches, and all of that information has been broken down in this article. Keep reading to discover everything you need to know about a go-kart clutch.

How a Go-Kart Clutch Works

When the clutch is activated, the go-kart can’t actually “go.” The clutch prevents the engine from engaging. When your foot is off the clutch pedal, the engine’s power can make its way through the kart’s different components. 

The engine’s power eventually makes its way to the gears and the wheels to make them move in a circular motion. With the clutch disengaged, your go-kart can now “go.”

The power transmitted from the engine to the wheels is referred to as “the load.” Pushing the clutch causes the whole assembly to disengage and the load to disconnect from the gears, and the kart to stop. 

When we think of a clutch, we think of the kind in a vehicle that works with the transmission to shift gears. Again, this isn’t the case with go-karts. With a go-kart, the clutch works on its own. When you step on a go-kart gas, the clutch goes to work, allowing the engine to run.

Engage the Load

“Engaging the load” is go-karting jargon for what happens when the vehicle gets the power to take off. The clutch is what enables the load to start slowly, instead of a giant burst of power all at once. 

As the driver, you’re also an engine component. Without you, there’s no way to push the gas. But once the gas is gradually pressed against the load member and the load member catches up to the engine’s speed over time until it causes the kart to go.

Both the engine driver and the load member components are disc-shaped. Think of it as placing a still disk on top of one that is spinning. The one on top will eventually begin to spin and continue to do so until it reaches the same speed as the disk below. 

During this period of transference in energy between the driver and the load, heat is given off as a byproduct of the parts’ frictional interaction. If it takes too long for the load to engage, the clutch could heat up excessively, causing heat damage. “Too long” is usually 10 to 15 seconds.

It is important to try to match up the clutch with the load system (gearing system) so that the heat generated is not too intense that it causes other problems. Too much heat will burn the clutch as it wears the material down. Eventually, heat damage will wear out the clutch completely, making it useless.

Disengage the Load

Go-karts are meant to go just a short distance. Once they’ve started, it’s usually not long before they need to be stopped. The clutch is also responsible for making that happen. When force is exerted unto the clutch, it causes the clutch to release from the spinning engine, and, as a result, the whole assembly also disengages.

Since the load and the engine are no longer connected as the clutch has disengaged, the kart will slow down and finally stop.

Types of Clutches Used in Go-Karts

Different types of clutches are used in go-karts. Each type has a different way of operating. This makes some clutches ideal for certain situations, while others will not be an option.

Centrifugal Clutches

Centrifugal clutches are the right choice for go-karts. They are the most inexpensive clutches on the market, going for around 30 to 40 dollars.  Besides the convenience in cost, they are easy to mount and beginner-friendly, so they have quite a bit going for them.

Centrifugal clutches are not exclusive to go-karts, but they fundamentally work by using centrifugal force. Centrifugal force is an outward force that acts on an object moving in a curved path to halt the movement: an inertial force. Centrifugal clutches employ centrifugal force to give the clutch the ability to engage and disengage the load.                                      

The engine shaft houses a weight system that propels the centrifugal force into motion, propelling the engine. As the centrifugal force increases in speed, so does the go-kart. 

Some higher-end centrifugal clutches will only engage the load when the engine runs at least 2000 to 3000 RPM. This is a reasonable number because typical engines can run around this amount (2000 – 3000 RPMs).

Variable Transmission Clutches

The upper hand of these clutches allows the go-kart to reach higher speeds even while the engine runs at lower speeds. 

A variable transmission clutch mechanism is two-pitch pulleys that are variable in size, with a constant length belt. It would help if you had the smaller pulley on the driver and the bigger pulley on the load member (called the driven pulley) for more torque.

Belt Clutches

These are not exactly the most efficient clutch system to use in a go-kart. To use belt clutches properly, you have to take in complex considerations of horsepower and the proper ratios to get the clutch system to work. When the ratios and the horsepower are not matched correctly, the engine could stall, and the belt could quickly burn up.

There are two systems the belt clutch system employs:

  • The belt tensioner system
  • The full belt tension system

The belts in each system work together, pulling on the belt and activating the clutch. The engine can spin freely while the belt is slacked. The belt can slip without damaging the belt within the engine’s driving pulley.

When the belt is tightened, the system is engaged. As the belt tightens, the belt gradually grabs at the clutch and stalls the system. The belt loosening and tightening action mimics that of a clutch: the clutch’s speed gradually increases until it matches the drive pulley’s speed.

Liquid Medium Clutches

These types of clutches work similarly to centrifugal clutches; they operate on speed. The clutch has two turbine wheels inside. The first wheel spins, causing an oil container to spill onto the second wheel, making it spin. Imagine a paddlewheel on a riverboat as water pours over it. The idea here is similar.  

Liquid medium clutches are ideal for go-kart tracks used for entertainment. Their durable clutches, so frequent use isn’t as much of an issue, as long as the clutch is well maintained. These types of clutches are durable. Most go-kart places that run their go-karts all-day use these types of clutches. 

The oil keeps the clutch lubricated, so heat damage isn’t as big of an issue. But, as you can imagine, there’s quite a bit of oil required, and that does become a hefty expense.

Electric Clutches

Electric clutches are battery-powered, so they’re a great option if you want a green go-kart. Once the battery is charged, it uses an electromagnet to spin an iron disk. 

The disk moves and blocks off the load, acting as a clutch. The force of this magnet’s engagement within the clutch system is related to the force that the electromagnet imposes on the system.

Typically, magnetic clutches go for anywhere between 60 dollars to 100 dollars, so they lean more towards the pricey side. They are often used in the air conditioning drivers of automobiles.

Hydraulic System Clutches

A hydraulic clutch system is the most versatile on this list. It is also the most complicated and the most expensive of the types of clutches discussed here. 

Building pressure is the principle on which this system is built. The hydraulic clutch works equally with a hydraulic engine, with a pump, hoses, and a hydraulic valve block. Once the clutch is engaged, the hydraulic motor inside the pump receives pressurized oil from the pump.

Hydraulic clutches aren’t known for their speed and performance, but they can be an effective clutch to use. If the hydraulic system isn’t maintained, it will lose its efficiency over time. 

Engines can end up stalling with a hydraulic clutch system if they are not properly matched to the system’s pumps and motors.

Suggested Go-Kart Clutches

There are plenty of options for clutches. If you’re building your kart from scratch, there’s a little more freedom to choose the clutch. If you’re in the market for a replacement clutch, your options will be more limited. Here are some of the top-rated go-kart clutches available.

ClutchKnow before you buy
LotFancy Go Kart ClutchWorks with gas engine go-karts¾” shaft bore sprocket. You’ll need to purchase the screws and chain separately.
Jeremywell 40 Series Torque Converter Kit ClutchThis model does not come with instructions.
A replacement option for other 40D Series Torq-A-Verter clutch models.
Centrifugal Clutch, Go Kart ClutchAmazon’s choice works with engines with a ¾” crankshaft; screws are included, and ain is not.
Mophorn Torque Converter Go Kart Clutch Go Kart Clutch Set Includes all necessary mounting hardware.

Proper Clutch Maintenance

To keep your go-kart clutch in good shape and operating for an extended time, there are some maintenance basics to keep in mind. 

Avoid Heat Damage

One significant way to avoid heat damage is to oil the clutch. As mentioned before, heat damage is the most common type of damage a clutch can incur and the type of damage you should seek to avoid the most. 

The reason for this is that when the clutch overheats, it will never disengage properly. As a result, the go-kart will be challenging to control. The clutch will take off by itself as soon as you start the engine of the go-kart.

The heat damage to the clutch is noticeable in the clutch drum. The metal will change color from black to blue (granted that it is black metal, to begin with). If you experience this condition in your clutch, you should change it because it has incurred irreversible damage. 

Keep the Clutch Lubricated

Before irreversible heat damage has the opportunity to occur, lubricate the clutch; after at least 2 hours of driving time for your go-kart, make sure to grease the bushing located within the clutch’s sprocket properly. 

If those riding the go-karts are small children, who characteristically will never push the go-kart to go fast enough and cause the clutch to work overtime such that it is always generating heat, you will need to oil it more often.

Lubricating the clutch is incredibly important, so it gets an entire section all to itself. Doing it the right way will ensure that your go-kart runs efficiently. Not doing it right can lead to all sorts of issues, including ruining the clutch altogether. 

What You’ll Need

Oil is, of course, the most important thing on the list of what you’ll need. You can use automotive oil to oil these parts, but oils are also made specifically for go-karts. Here are a few go-kart oils that work well:

It’s also important to know what you should not use to oil your go-kart clutch. Slick 50, Dynamite, or Energy Release are all types of internal engine oils you should not use on your clutch at all. They will cause significant damage if they get into the engine of your go-kart.

How to Lubricate the Clutch

  1. You will not put the oil directly inside the clutch. There are holes on the drum that let hot air out of the clutch. Squirting oil into these holes is about the worst thing you can do. It would end up trapping the heat inside the clutch and further damaging it.
  2. Instead, you will want to put the oil into an internal bronze bushing behind the snap ring at the end of the clutch, next to the sprocket ring. This bronze bushing requires consistent lubrication. This is the reason why it is essential to oil the clutch consistently.
  3. It is also advisable to oil the chain (if there is one) when you oil the internal bushing. The chain gets kinks in it from a lack of oiling. It can also damage the clutch sprocket and should be replaced.
  4. Use automotive oil to oil these parts. Find out about the proper type of automotive oil for the clutch you have with an expert. 
  5. For a go-kart with a grease fitting in the crankshaft, that fitting offers consistent lubrication by spraying out grease from the inside of the sprocket outward. This is a better way to lubricate the clutch, and if it exists, you may only need to oil the Clutch two times a month for upkeep.
  6. An excellent way to gauge whether or not the clutch needs lubrication is to carefully study the kart’s performance when it revs up and when it moves. If the go-kart takes off by itself when the engine starts, while there is no individual in the driver’s seat, the clutch needs to be oiled.
  7. If that situation does occur, the best way to oil the go-kart’s clutch is to recline it against a sturdy object like a tree and turn the engine off before lubricating the clutch. Let the lube penetrate properly into the clutch before testing the start again. Allow the go-to kart to remain situated against the sturdy object when you turn on and test the start so that it does not run away again.

How to Replace a Burnt Out Clutch

When a clutch is improperly installed or driven in abusive conditions, the opposite is true. In that case, the clutch may not even last beyond 30 minutes.

If the clutch burns out, you need to remove it and replace it. Removal is a reasonably easy job. 

  1. It is key to make sure that all the parts of the old clutch are removed. Thinking it has been fully removed is a common mistake, so it is necessary to go back and inspect carefully and remove all the left behind pieces.
  2. A particular difficult piece of the clutch is the clutch hub. Clean your crankshaft with a wire brush if the crankshaft is rusty. Get as much rust out of the end of the crankshaft as possible and spray some oil that can penetrate between the clutch hub and the crankshaft.
  3. There are usually two sets of screws binding the clutch hub to the shaft. So, remove these screws so that you can remove the clutch hub. If the clutch is in pieces, remove those pieces until only the clutch hub remains attached. With all the other pieces removed, you should use a gear puller to pull it off.
  4. After removing all the burnt-out, old clutch pieces, proceed to clean the space left behind completely and then attach your new hub in that location.

Don’t Let Just Anyone Drive Your Go-Kart

The one(s) driving the go-kart will affect the life span of the clutch as well. Properly educating any and all drivers on good driving practices will allow the clutch system to last longer, as well as the go-kart itself. Make sure everyone knows the rules before they climb in for a ride. Let the drivers know that the following driving habits can ruin the clutch.

Driving Too Slowly

Certain types of clutches will only start to engage around 2000 rpm and above: a centrifugal clutch (which is the most common clutch used), for example, behaves this way. Driving at speeds that allow the clutch to be fully engaged will enable it to cool down as it will not be heating up, trying to get the load to engage for more extended periods. 

When the clutch is not engaged, it does not lock into place against its drum, which causes a tremendous amount of heat to generate, fry up the clutch’s lubrication, and sometimes anneal the heart of the clutch, which is the spring.

Showing the driver what speeds are ideal for the machine’s optimum performance and what those speeds look and feel like driving is a great way to kill two birds with one stone: promoting go-kart safety and optimum performance.

Short Stop and Go Driving

Driving for a more extended period is better for the clutch because it gives it a chance to cool off before using and heating up again. When the clutch is fully engaged, there is no wear on it. Equally, when the clutch is disengaged, there is no wear on it. But as the clutch is engaging or disengaging, it is put under strain.

So, when the go-kart is made to stop and go in quick succession continuously, it will cause the clutch to wear out quickly. Show the driver to try and keep driving without stopping abruptly as the ride in the go-kart.

Riding the Brake

New drivers that are unsure of themselves tend to make this mistake mostly because they have not yet become familiar with the difference between the brake pedals and the gas pedals. But as you drive with your foot on the brake, conflicting things will occur. 

The driver will reflexively hit the brakes continuously while trying to propel themselves forward.

A driver needs to build up confidence in driving the go-kart before being put on a track or in a rink with many obstacles that need to be maneuvered.

Mismatching Tire Size 

Placing tires larger than the original tires placed on the go-kart at the beginning will also cause problems by putting a strain on the clutch. Keep in mind that the clutch serves to transfer the engine’s power into the kart’s wheels to cause mechanical movement.

Therefore, if the tires are larger than anticipated for the original clutch, they will have to deal with more weight and struggle to perform at its optimum. Tires that are ill-fitting or not correctly sized become an even bigger issue if the terrain is not smooth, and the kart had to navigate obstacles.

Weight

Most clutches are affected by weight. A centrifugal clutch, for example, fits in this category. It is designed to be able to move a certain amount of weight. That is why mismatching the tire size, as mentioned previously, can adversely affect the clutch. When the weight the clutch can carry is exceeded, its life span is being significantly shortened. 

As a good rule of thumb, the go-karts, along with the driver and a front passenger, should not exceed a weight of 400 pounds when weighed together. Most karts will weigh around 150 pounds, and then the driver and front passenger will have 250 pounds of leeway.

Don’t Use Restrictors on the Clutch

Applying limitations to your kart will harm the clutch. For example, you may try to reduce the kart’s speed by putting a limit on the gas pedal travel. Or, you put a restrictor in the carburetor to limit the kart’s full rpm.

If you apply any of these tactics, the result will be the Clutch slipping. These methods are self-destructive. The clutch needs the go kart’s full rpm to lock up after engaging the load and cool down. 

The only way to safely install limits on the go-kart is first to install a gear reduction unit. 

The Lifespan of a Clutch

The lifespan of your go-kart clutch will depend, to some extent, on the type of clutch installed in the kart, how well maintenance is run on it, and how it is used. If a clutch is properly maintained, observing all the requirements delineated in this article, it should be able to last several years before needing a replacement.

Of the clutches discussed in this article, the hydraulic clutch promises to have the highest life span in most cases. Notwithstanding, other types of clutches will equally hold up for a reasonable time exceeding five years.

Final Thoughts

The clutch of a go-kart is a critical component to making the go-kart go. However, a go-karts’ clutch has a different function than that of a car, which is commonly what we think of when it comes to clutches. 

A clutch is a component that controls the karts’ ability to start and stop. This makes it a key and critical part of keeping those within the kart safe from engine combustion and the like. 

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