Frequently Asked Questions – 3D Motorsport Engineering
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    1. 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. The vast majority of users may never have to replace the discs. However, if the disc thickness drops below .093" thick, the disc should be replaced. 


    2. 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.


    3. 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.


    4. 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.


    5. 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.


    6. 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.


    7. 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.


    8. 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.


     9. 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. 


    10. 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.


    12. 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 reason is that the 3DME Manual Clutch allows energy stored in the flywheel to be instantaneously released once the clutch lever is released. This surge of energy causes a spike in rear wheel torque, making the front end lift off the ground.

    For trail riding, the 3DME Manual Clutch provides a significant advantage because it allows the rider to loft the front wheel over obstacles.


    13. Are any special tools required to assemble and disassemble 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. Also, you need a set of external retaining ring pliers and a 5/64 hex wrench.


    14. 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 to discuss your application in further detail.


     15. 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.


    16. I'm trying to decide between a multidisc centrifugal racing clutch and the 3DME Manual Clutch. Why is the 3DME Manual Clutch better?

    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 kills a centrifugal clutch out of the gate every time.

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

    Lastly, as centrifugal clutches wear, the engagement speed changes. It takes pretty consistent adjustment and fine tuning to keep a centrifugal clutch engaging at ideal RPM. When the RPM can no longer be achieved through tuning, the clutch requires a lengthy and expensive rebuild that requires precision machining of many of the internal components. The 3DME manual clutch on the other hand will engage at exactly the RPM you dictate, no matter how worn out it gets. 


     17. What is the refund policy?

    All products that 3D Motorsport Engineering sells are 100% refundable if there is a manufacturing defect with the product(s) received. For example, if parts are damaged or missing, that particular item is eligible for a full refund after the product is shipped back to us.


    18. 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.