Frequently Asked Questions

Is a manual clutch right for my application?

Maybe... This clutch is dry and small, so inherently not meant to slip. Engagement is off/on, unlike larger clutches in a motorcycle or car. Depending on your drive ratio and traction, starting may be difficult to not kill your motor. This clutch is great for small-wheel / low-gear mini-bikes, burnouts, drift-karts, drift-trikes, some dirt, some racing, and various specialty applications. If you want to control drivetrain engagement regardless of engine speed, this clutch is for you. If you are a casual cruiser, or you rely on the ratio range of a torque converter, this clutch probably is not for you. It gives your drivetrain a strong direct connection to the motor with no slip, engaged when you want.

When will I know if the clutch discs need to be replaced?

The friction disc facings are made of very hard and wear resistant ceramic brass material. As a result, the wear life is exceptionally long. Whenever the clutch stays firmly engaged, discs are not wearing at all. If you insist on slipping the clutch too much, discs may wear quickly. The vast majority of users may never have to replace the discs. If a disc is heat-glazed or thickness drops below .093" thick, the disc should be replaced.

Is the 3DME Manual Clutch safe for my young son or daughter?

The 3DME manual clutch is as safe as any other clutch. Safety depends more on your vehicle and rider skill. The 3DME manual clutch can help teach proper clutch technique that will carry over to other vehicles with manual transmissions.

How large is the 3DME manual clutch relative to the PTO shaft of the engine?

The length will be longer than almost all PTO shafts. Most shafts are approximately 2.375" long. The 3DME Manual Clutch is approximately 3.125" long. For additional dimensions, please see the "3D Manual Clutch Basic Dimensions" webpage located in technical info.

Will the 3DME Manual Clutch work on any engine with a 3/4" straight PTO shaft?

Yes, the 3DME Manual Clutch is a universal bolt on unit designed for use on an utility engine that has a 3/4" keyed PTO shaft. This includes Briggs & Stratton, Honda, Tecumseh, Honda Clone, Predator, etc. It will also work on electric motors and engines using a shaft adapter.

Can the 3DME Manual Clutch be used in wet/muddy/dusty conditions?

Yes, the 3DME Manual Clutch uses sealed bearings to exclude dirt/moisture and retain lubrication. However, the clutch should be disassembled and cleaned periodically for optimal performance and service life. The bearings are sealed and greased for life. If you believe that the bearings have been damaged or contaminated, we supply replacement items.

Does 3D Motorsport and Engineering plan to offer a 1.0" version of the manual clutch?

Maybe... We certainly would like a 1" version, but not sure there is enough market demand. I'm watching the sales rate for the current product and tracking all inquiries for a larger version. There are no firm plans to expand.

Do I have to use the clutch guard that comes with the 3DME Manual Clutch or can I use my own?

Besides protecting the rider from rotating parts, the clutch guard is the mounting point for the actuator bracket and cable housing. A custom clutch guard could work as long as it holds the anti-rotation bracket and actuator cable.

How do I disassemble and reassemble the 3DME Manual Clutch?

To disassemble the clutch, you need to compress it, such as with the 3DME service tool. Otherwise, the bolts are under lots of tension. And, you can't thread those bolts back in without compressing the clutch.

Does the 3DME Manual Clutch allow for gear shifts?

By itself, the 3DME Manual Clutch will not give your bike or kart gears to shift. However, the manual clutch enables you to add a transmission of your choice to your bike or kart.

Will the clutch perform better with the governor removed from my engine?

Absolutely. You will get the most performance out of your engine if the engine is able to rev beyond its peak torque RPM. While most engines are governed to 3600 RPM, their peak torque is typically between 4000-4500 RPM. Additionally, higher engine RPM stores more energy in the flywheel which can be used to accelerate the mini-bike or kart more quickly.

3D Motorsport and Engineering strongly recommends that a billet aluminum flywheel and connecting rod be installed prior to removing the governor. Stock flywheels and connecting rods are not designed to withstand RPM beyond 3600 RPM.

Does the 3DME Manual Clutch make wheelies easier on a mini-bike?

Definitely. One of our test bikes is a DB30 with a predator 212. Using 12-70 gearing, we can easily initiate a wheelie at nearly 15 MPH by pulling the clutch lever in, increasing engine RPM, and releasing the clutch. The front wheel comes up with relative ease. The manual clutch allows flywheel energy to transfer instantaneously when the lever is released. For trail riding, the manual clutch allows a rider to loft the front wheel over obstacles.

Are any special tools required to assemble and disassemble the 3DME manual clutch?

Can the 3DME Manual Clutch be used for industrial applications, or other applications not related to mini-bikes and go-karts?

Absolutely! The clutch is extremely versatile and we have had customers install them in tractors, machine tools, and even super-mileage vehicles. Email info@3dmotorsport.net to discuss your application in further detail.

Is it normal for the clutch to make noise when it is disengaged (lever pulled in)?

Yes. Like all dry running disc clutches, the 3DME manual clutch will produce a slight amount of noise that is very similar to the noise that Ducati Sport Bike clutches make. When the clutch is disengaged, the friction disc outer tangs are able to rattle against the slots in the clutch basket which results in a rattling noise. That noise is completely normal.

Should I choose a multidisc centrifugal racing clutch or the 3DME Manual Clutch?

Modern centrifugal racing clutches are superbly designed and manufactured. RPM engagement is completely adjustable, so they can be tuned to engage consistently at or near peak torque RPM. But by design, they can never fully convert all engine/flywheel energy into rear wheel torque. Although it takes more skill to operate, when mastered, a 3DME manual clutch will connect 100% of your engine power to your drivetrain.

Centrifugal race clutches are only good for one thing: racing. They can be easily damaged or destroyed when in use for less aggressive riding. The 3DME manual clutch engages equally as well on a 3hp mini-bike as it does on a 15 horsepower race kart.

Lastly, as centrifugal race clutches wear, their engagement speed changes. It takes consistent adjustment and fine tuning to keep it engaging at ideal RPM. When the RPM can no longer be achieved through tuning, the clutch requires a rebuild with precision machining of internal components. The 3DME manual clutch always will engage at the RPM you dictate.

How much does the 3DME Manual Clutch weigh?

The clutch itself (i.e. the part that mounts to the shaft of the engine) weighs 3.1 pounds. More important for performance, the rotating components weigh 2.25 pounds. The clutch guard and associated fasteners will add an additional 1.4 pounds.

What is the return policy?

3D Motorsport Engineering backs all products sold. If parts arrive damaged or missing, we will quickly send replacements.

If you change your mind before installing, the product is unused and may be resold as new, then we will refund product costs (but not shipping), after it is shipped back to us.

All clutches are tested to disengage/engage before packaging. If your clutch does not actuate, please contact us. It is probably something simple. If we cannot resolve a manufacturing defect, we will replace or refund your clutch upon return.

We do not know your application (unless you ask us beforehand), and we do not take responsibility for your buying decision. If the product works as stated, but does not match your application after using it, that is on you. Out of good faith, however, we may offer case-by-case returns with a partial refund for returns made within a month of purchase.