The tension on your kart’s chain is crucial to get right. If it’s too tight you can damage and wear out both the chain and the sprocket. If it’s too loose then you run the risk of the chain falling off entirely while driving.
In both cases it can also affect the performance of your kart. If the chain is too tight, there will be too much friction on the sprocket, and it will struggle to turn the wheels. On the other hand, if it is too loose there will not be enough grip between the sprocket and the chain, causing a lack of drive.
If you’re new to karting it can be difficult to find the right amount of tension on the chain, however over time it becomes second nature and you’ll be able to get the tension right with ease. There should be a little bit of play (flex) on the chain when you push it up or down.
The right amount of play is usually about an inch. When you look at the chain, it should not be hanging at the mid-point, this would indicate that the chain is too loose. In order to adjust the tension on the chain there a few different methods you can use:
The first step you should try is to loosen the engine mount and move it slightly forwards or backwards on the chassis. Some engine mounts have a slide feature, so just by loosening the mount you can slide the engine as required. Where people get caught out is, as they tighten the engine mount it tightens the chain slightly once the engine is pulled down on the mount.
If your mount doesn’t have the slide feature, you can still loosen the mount and move back & forth as required. Most karts are fitted with an engine stop bolt behind the engine. This can be loosened, then adjusted to stop the engine from moving any further back. Once you’re happy with the tension, tighten the engine stop and tighten the mount.
You can also adjust the tension on the chain by adding or removing links. You can do this by using a chain link removal tool. This is the easiest way to adjust the actual length of the chain.
Make sure you measure how many links you need to take out of the chain. You can do this by using folding some of the links together until you find the right level of tension. The other option is to use trial and error and remove links until you find the correct level of tension, but this will take longer.
The first step here is to remove the chain from the kart. In order to do so you might need to remove the clutch cover. Once the clutch cover is off you can simply take the chain off the sprocket. Next you will need to find the master link which will look distinctly differently from the rest, it might have a clip, or in some cases could even be a different colour.
The master link on the chain will have a small clip that you can undo with a pair of pliers, and then you can carefully push the two pins out of the link. Make sure to keep the clip in a safe place because you will need to put it back on later.
When you are adding or removing links you want to do so with the links directly next to the master link. Place the chain onto your link removal tool ensuring that the pins are against the screw. Then you adjust the screw until the pin releases the link, but do not remove the pin from the link. It’s easy to lose pins when they’re detached from the links. You can reattach links in the same way using the chain link removal tool.
Repeat the process until you have added or removed as many links as you need on the chain. Remember to double check the tension on the chain afterwards to make sure that it is right before you start driving. You may need to adjust the length of the chain if you are changing sprockets. The sprockets are different sizes and have different amounts of ‘teeth’ which affects how tight the chain needs to be on your kart.
Why does my chain come loose?
Chains are subject to wear and tear. The higher performance the kart, the quicker chains wear out. If you lubricate your chain after each on track session this gives it the best chance to remain in good condition.
For faster categories O-Ring chains are the best for longevity. So although the initial outlay might seem a bit steep, the extra milage you get from the chain is worthwhile.
If you can pull the chain off the sprocket once everything is fitted, this is a sign the chain is worn out and past it’s used by date. Checking the sprocket and chain after a race weekend is a wise idea, as one is wearing the other will wear at a quicker rate also. It’s advised to change them both at the same time.