It’s not very uncommon that you buy a centrifugal clutch and 2-3 days of use later, you’re scratching your head thinking what’s gone wrong with this thing.
If you’re not taking good care of your clutch, you will ruin it, I’m assuming that most people who are reading this article have already got a problem with it, but if you’ve still got a brand new clutch, put the proper time into maintaining your clutch.
You can read more about maintenance in the how to install a centrifugal clutch article.
Clutch stuck to the crankshaft:
This is not an uncommon problem, people ask all the time about how to remove your go-kart clutch.
It could have happened if you gave the key some tap while installing the clutch.
Firstly, you’ll need an oil that can loosen frozen metals, spray them and let them soak in. The Kano Aerokroil oil is very useful for this purpose. If it’s still not coming out, then you’re going to need a 3 jaw gear puller to pull the clutch out, but do keep in mind that if the clutch is stuck real tight then the puller can be damaging to the clutch. Oil it several times before you move on to the gear puller solution.
Before putting on a new clutch I highly recommend applying some anti-seize onto the crankshaft, it will make disassembling easier the next time.
Centrifugal clutch engaging at idle
There are a few reasons why your clutch is engaging at idle:
- The RPM at which the clutch engages is lower than the idle RPM of your Engine
- Your clutch has suffered heat damages due to lack of maintainance.
The popular Predator 212 has an idle rpm of 1800, so if your clutch engages at an rpm lower than the idle speed, then the go-kart or your mini-bike will take off as soon as you start the engine.
Fix for high idle RPM Engines:
The fix for it is to either get a new clutch with a higher engagement rpm or the better and cheaper option is to change the idle speed of the engine, to change the idle speed of the engine, you’ll have to find an idle screw in the engine.
In Predator 212, a black screw can be found just above the carburetor, if you turn it counterclockwise the idle will lower and if you turn it clockwise the idle will increase. You can try on different idle speeds to find the one at which the clutch isn’t engaging.
Fix for the clutch stuck due to heat damage:
The other reason why the clutch is engaging at idle(and the more common reason) is that the clutch has suffered heat damage and the shoes in the clutch are not disengaging.
To solve the overheated clutch problem, you’ll first need to take the whole clutch apart, for that you’ll need a snap ring plier, you can read about the whole process of taking your clutch apart in the “Adjusting the go-kart clutch” section of this article (just read on till the part of disassembling the clutch, do not shorten the spring)
Once you have your clutch disassembled take a look at the shoes, if you see discoloration then the surface has formed an oxide layer, to remove this, take a sandpaper and start sanding the outer surface of the shoes. Keep the surface even.
Use just a little grease on the outer surface of the shoes and the base holding the shoes. Put the whole clutch back together. Remove all the grease from the surface of the outer surface of the shoes (the part which comes in contact with the drum), it should not have any grease on it otherwise the surface will slip cause even more heat damage.
If this still doesn’t solve the problem, it’s time to get a new clutch and this time keep the bushings properly oiled.
Overheating of clutch
If your clutch is starting to release smoke or is releasing sparks then it’s likely due to overheating. Overheating can be caused by a variety of reasons:
- Lack of oiling/lubrication
- Rear tires too large for the gear ratio
- Engine horsepower too high for the clutch
- Too much weight o the go kart
- Driving go-kart on low speed for long time.
Oiling or grease lubrication is a must-do after every few rides, it will reducing friction, heat, and wear between the bushing and the crankshaft.
If your rear tire is too large for the gear ratio, that too will cause a lot of heating, ideally, the gear ratio for a 13″ tire is 1:6, (Gear ratio=teeth in clutch sprocket: teeth in axle sprocket), if you want larger tires then you’ll need to decrease the ratio accordingly.
It might be surprising but driving at low speed for too long can also cause a lot of heating, this is because the clutch releases heat when fully engaged, cooling itself down.
There are loads of problems that you can run into that are not mentioned here, if you’re unable to find a solution on the internet, you can send us an email and we’ll get back to you, or you can find a lot of online forums with tons of knowledgable people that can help you.
It’s also important to note that a poor quality clutch will always run into more problems, here is our list for the best small engine go-kart clutches.