Thirty or forty series Torque converter/CVTs are frequently utilized in Minibikes and Go-Kart for power transmission from your engine to its wheels; if you have one of such in the setup, it is very likely that you’d have run across some issue. The majority of the issues are usually because of the unaligned pulleys and the wrong selection of belts. We’ll glance at a few of the common issues in this guide.

Go-Kart Torque Converter Jerking:

It frequently happens that you face a jerk when you speed up the torque converter from 0.


Check your belt size chart and make certain you are making use of the precise belt. If the belt size is precise, then take off the driver unit for cleaning and lubricating it. Make certain the throttle cable is installed correctly; lubricate your drive chain after some rides. Replace your chain if it has worn out. Check if your engine is functioning properly.

Torque Converter Belt Slipping:

Potential Issue:

  • Wrong Belt size and/or symmetry
  • Drive/Driven components worn out
  • Pulleys not aligned


First of all, you have to check whether the belt you are making use of is the right belt for the setup. If you own a symmetric belt in a thirty series, for instance, that’ll cause issues. It is a great idea to see whether the belt you own is the right belt; the majority of issues you come across will likely be because of utilizing the wrong belt in the setup.

Now once you are certain that the belt is the right belt, next see whether you’ve installed the torque converter properly and the driven and driver pulleys are aligned correctly (you can locate a lot of YouTube videos on how you can install your torque converter’s version, setup can be diverse for diverse series, for instance, thirty series setup is a little diverse from forty series).

If it all checks out, then the issue is either the components inside your torque converter or the Gear ratio (axle sprocket: CVT sprocket) is really high. See whether the driven or driver components are worn down at the surface which holds your belt; the slip is possibly caused by such wear. In such cases, you’ll need to replace those components if the damage is really heavy.

Driven Pulley/Go-Kart Moving At Idle:

The go-kart ought not to be moving at idle; otherwise, it’ll take off as soon as you start your engine, and any engine has the pre-set idle RPM, which can easily be adjusted. If the driven clutch is beginning to engage at the idle RPM, then the idle speed is really high for the weight-spring system in your clutch.

If your clutch isn’t engaging, but your go-kart is still moving, it is likely the belt problem, i.e., you have a tighter belt than the one needed for the set-up.


If your clutch is engaging, you have two choices:

  • Change the weight-spring system in the clutch; a stiffer spring with a lighter weight will upsurge the engagement RPM.
  • Reduce the idle speed of your engine, there are idle screws in your engines, and if you loosen them, the engine’s idle speed will reduce.

If the problem isn’t related to the clutch engagement, then see whether you are making use of the right size belt or not; more likely, you have the tighter belt that’s pulling the driven at idle.

Torque Converter Sticking:

Took the foot off the gas, but your clutch never disengaged? A lot of individuals have this issue with the series forty, you take your foot off the gas and anticipate the pulleys to go back to their idle state, but they seize up.


In the forty series, such jams frequently happen because of the spring-weight system not being capable of moving simply, so you will have to take the clutch apart and clean and lubricate the inside components of your movable clutch (make certain not to append any lubrication to the components in contact with your belt, that’ll ruin the torque converter).

If even after proper greasing and cleaning, the issue continues, it is likely because of the torque converter not being of great quality, or the outer component of your clutch may be really big, making it difficult to slide back. In such situations, unluckily, the best fix is to get a brand new great, quality torque converter.

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Belt Wearing Problems:

The most common problem is the belt getting worn out. Reasons:

  • Use of wrong belt length for the torque converter (most common)
  • Driven and drive pulleys not aligned
  • Torque converter not installed correctly
  • Bad Gear ratio (sprocket in axle: sprocket in the Torque converter) with big tires. 6:1 is a good, common ratio for a fifteen inches back tire; bigger tires and a high ratio will cause issues
  • Slippage because of wear in metals
  • Bad quality belt


Make certain the torque converter is correctly installed; if your belt is asymmetric, then the tapered side will be towards your clutch, and the non-tapered one will be towards your engine.

Make certain you’re not putting a lot of load on the kart unless the gear ratio is attuned accordingly; by the load, I denote pulling a heavy load or climbing the hills; such actions need high torque. Check your pulley alignment. Select the correct belt length. Clean and lubricate your torque converter at regular intervals.


These are the most common issues in your torque converter frequently; the fix lies with your belt size and good installation and time-to-time maintenance. At times, the torque converter itself could be of bad quality. But obviously, I know each setup is diverse, and you may face an issue very unique to you;

I recommend you learn how your torque converter really functions, and you may be capable of discovering the solution yourself.

Other than that, there are some active kart forums; very likely, the issues you’re experiencing have already been debated in such forums, or you can send the pictures of the setup and elucidate the issues, and the community will assist you in resolving the issue.