Top 5 Best Clutches for 1-inch Shaft

Engines such as Predator 420cc, GX 390, and other bigger block engines with 1″ diameter shaft require a clutch with a 1″ bore. In this buying guide, we will go through the best clutches for Predator 420 and other GX390 clones.

Note: If you’re unsure about the shaft diameter of your engine, make sure to take measurements before buying a clutch. If your engine has a 3/4″ shaft diameter then check our list of best clutches for predator 212.

Top 5 Best Clutch for 1″ Shaft Engines

1. EASYBERG Centrifugal Clutch – Best Value for Money (#40/41/420 Chain)
2. AlveyTech – Best Quality
3. Hilliard Extreme Duty – Heavy Duty Clutch compatible with #35 Chain
4. Jeremywell 1″ Centrifugal Clutch – Heavy Duty Clutch compatible with #40/41/420 Chain
5. Noram Enforcer – Best Racing Clutch

1. EASYBERG Centrifugal Clutch

Easyberg’s 1″ clutch is the most value for money clutch and will work with any engine that produces 13 hp power, so it will work with Predator 420 or Honda GX390.

The clutch engages at 2100 rpm which can be increased with stiffer springs. It is also bi-directional, i.e, the clutch can be installed with the face towards the engine or away from the engine.

It has 14 teeth and is compatible with #40,41 or 420 chains. 14 teeth might result in gearing set too high and can burn this clutch. In such cases, you can either install a jackshaft to decrease gearing or buy a different clutch with less number of teeth.

Note: High gearing will burn this clutch, which you might be able to read from this product’s reviews. Make sure to keep the gearing at least 6:1.

2. AlveyTech

AlveyTech’s 1″ clutch is a heavy-duty clutch and is made of high-quality materials that will last a long time in comparison to other Chinese-made clutches.

It comes with 12 teeth and is compatible with the #35 chain. 12 teeth will make it easier for you to gear the go-kart correctly. The clutch will engage at 2000 rpm.

3. Hilliard Extreme Duty

Another heavy-duty clutch, this one is made by Hilliard. Hillard clutches are really high quality and will last a long time. It will engage at 2300 rpm and work perfectly fine for a 13 hp engine.

It will come with a #35 chain and 17 teeth, which will naturally result in high gearing but the clutch is of good quality and will likely be able to withstand high gearing unless you’re using huge tires!

4. Jeremywell Clutch

This is another heavy-duty clutch but rather than the #35 chain, this one is compatible with the #40, 41, or 420 chains. However, this will only work well for engines that produce under 9 hp power.

Therefore, it is good for engines such as Predator 301 but will burn quickly if used with Predator 420 or GX390 and its clones such as Duromax’s 18 hp engine. It can be used on a 10+ hp motor if the springs inside the clutch are made stiffer.

5. Noram Enforcer

Noram is known for its racing clutches, and this one here is a 1″ bore clutch that will work with engines that produce up to 20 hp.

Racing clutches are designed for high efficiency so that most energy can be transferred to the axle. Apart from “Enforcer”, Noram also makes “Noram Star Clutch” which are a little cheaper racing engines.

These engines are perfect for modified engines, it will give you an edge on the race track.

FAQ

1. Clutch vs Torque Converter

On a big engine with a 1″ bore, Torque converters are usually a better choice because they will last for a longer duration. Clutches are very likely to burn out if not looked after properly. Torque converters are much better suited to handle the power produced by these engines.

However, Clutches are much more power-efficient and will give you the extra few mph in comparison to Torque Converter. If your purpose is racing and your budget is high, then choose a racing clutch but if your go-kart is off-road/fun kart, choose a torque converter.

2. How many Teeth is Good?

The number of teeth will determine the gearing of your go-kart, there is no one magic number that will be good for all, the best for your purpose depends on your engine and tire size, you can check our gearing chart to get a general idea.

To give an example, if your tire is 15-16″ and the engine produces 13 hp, then you should have the gearing set to at least 5:1.

Note: The quality of the clutch also matters, high quality clutch can withstand high gearing.