These parts may also fit the following racing mini quads 2 stroke 90cc Apex 90cc Artic Cat Polaris 90cc Eton 90cc Kasea 90cc ATV Can Am 2 stroke 90cc ATV, Kymco 90cc atvs, Standard Motors and Borosa plus most minarelli Horizontal scooter engines. The parts can also be used to upgrade Racing Scooters for the following Yamaha scooters as the Yamaha jog, Yamaha Zuma , Kymco scooters only 2 stroke two Eton two-stroke scooters, Kasea scooters and standard motor 90cc scooters. You must check fitment before ordering to ensure the parts will work on your 90cc scooter or ATV.
A Small Washer With an Important Job
When servicing the front variator on a DRR ATV, it may be tempting to reuse the star-shaped washer behind the variator nut. It may still look usable after removal, but this washer is designed as a one-time-use crush washer.
Every time the front variator is removed, the star washer should be replaced.
The washer is part of the variator’s fastening system. It helps the variator nut maintain the correct clamping force while the engine and continuously variable transmission, or CVT, are operating. Because the washer changes shape when the nut is torqued, it cannot reliably perform the same job a second time.
What Happens When the Variator Nut Is Torqued?
As the variator nut is tightened to the manufacturer’s specified torque, the washer is compressed between the nut and the variator assembly.
This compression causes a controlled amount of permanent deformation. The washer may flatten, compress, or conform to the surfaces around it. This is why it is commonly called a crush washer.
That deformation serves several purposes:
It helps create consistent clamping pressure.
It helps the washer conform to small surface irregularities.
It increases resistance to movement in the fastener stack.
It helps the variator nut remain secure during vibration, acceleration, deceleration, and repeated engine-speed changes.
The washer’s splined center and star-shaped outer profile also help it fit correctly within the variator assembly. However, the main protection still comes from the correct installation order and proper clamping force.
Once the washer has been fully compressed, some of its original shape and elasticity are permanently lost.
Why the Star Washer Is a One-Time-Use Part
A new washer begins with the thickness and shape needed to deform correctly during installation. A previously torqued washer has already gone through that process.
When an old washer is installed again, several problems can occur.
It May Not Compress Correctly
A used washer is already flattened or distorted. When the nut is torqued again, the washer may not provide the same controlled compression as a new part.
The torque wrench may indicate that the correct torque has been reached, but the actual clamping force on the variator assembly may be different.
Torque is only an indirect way of creating clamp load. Changes in washer thickness, surface condition, friction, or deformation can change the relationship between the torque applied and the force holding the parts together.
It May No Longer Maintain Tension
A new crush washer can help accommodate minor movement and settling within the variator stack. After it has been compressed, its ability to maintain that tension is reduced.
CVT components experience constant vibration, rapid speed changes, heat cycles, and changing loads. A reused washer may not compensate for those conditions as effectively as a new one.
The Washer May Be Work-Hardened
Metal changes when it is bent, compressed, or deformed. After being crushed during the first installation, the washer may become harder and less able to deform evenly during a second installation.
Instead of compressing as designed, it may crack, distort unevenly, or create pressure in the wrong areas.
Its Teeth or Splines May Be Worn
The washer’s center opening fits around the splined portion of the shaft. Removal and installation can wear, round, or distort those internal edges.
Even minor wear can allow unwanted movement between parts. That movement can lead to fretting, metal debris, damaged splines, or an improperly secured variator assembly.
Its Contact Surfaces May Be Damaged
A used washer may have grooves, raised edges, burrs, or polished areas from the variator nut and surrounding components.
These surface changes affect friction. Because friction has a major influence on fastener torque, a damaged washer can produce an incorrect clamp load even when the nut is tightened to the specified value.
What Can Happen When a Used Washer Is Reinstalled?
Reusing the star washer creates a risk that the variator nut will not remain properly secured.
Possible results include:
A Loose Variator Nut
If the washer cannot maintain the proper clamping force, the nut may begin to loosen while the engine is running.
A loose variator nut should never be treated as a minor issue. The variator rotates at engine speed and transfers power through the CVT belt.
Variator Movement and Wobble
Insufficient clamping force can allow the drive face, fan, or other variator components to move on the crankshaft.
That movement can produce vibration, unusual noises, inconsistent belt operation, and uneven component wear.
Damaged Crankshaft Splines
When variator components move against the crankshaft instead of remaining tightly clamped, the splines can become rounded, stripped, or hammered out.
Replacing a washer is inexpensive. Repairing or replacing a damaged crankshaft is not.
Damaged Variator Components
A loose assembly can damage the variator fan, drive face, ramp plate, nut, spacers, or other parts in the fastening stack.
Even if the ATV continues to run, damaged or misaligned parts can reduce CVT performance and create a larger failure later.
Belt Damage
The CVT belt must run between correctly aligned pulley faces. If the front variator becomes loose or misaligned, the belt may run unevenly, overheat, fray, or fail.
Sudden Loss of Drive
A severely loose variator assembly can stop transferring power properly. In extreme cases, parts can separate or suffer major mechanical damage inside the CVT cover.
Do Not Try to Restore a Used Washer
A used star washer should not be flattened with a hammer, bent back into shape, sanded, or otherwise repaired.
These methods do not restore the washer’s original material properties, dimensions, or controlled crush characteristics. They may also create cracks or uneven surfaces that are difficult to see.
The correct repair is replacement.
Best Practices During Front Variator Service
Whenever the front variator is removed:
Discard the used star washer.
Clean and inspect the crankshaft threads and splines.
Inspect the variator nut for thread or contact-surface damage.
Confirm that all spacers, washers, drive faces, and variator components are installed in the correct order.
Make sure the CVT belt is not trapped between the pulley faces during tightening.
Install a new, correct star washer.
Tighten the variator nut to the exact specification listed in the service information for that model.
Use the proper variator-holding tool whenever the service procedure calls for one. Do not depend on uncontrolled impact-wrench force as a substitute for the specified tightening procedure.
Thread-locking compound should not be added unless it is specifically required by the manufacturer. Thread locker cannot compensate for a damaged, reused, or incorrect washer.
Confirm the Correct Washer and Torque Specification
DRR models and engine configurations can use different parts and torque values. Always confirm the correct washer, variator assembly order, and tightening specification for the exact ATV being serviced.
Replacement clutch and variator components for applicable DRR DRX models can be found through the DRR ATV Parts clutch section.
Replace It Every Time
The front variator star washer is not an ordinary reusable flat washer. It is a service part designed to deform when the variator nut is torqued.
Once it has been crushed, it cannot be expected to deliver the same fit, tension, friction, or clamping performance again.
Replacing it every time the variator is removed helps protect the variator, CVT belt, crankshaft splines, and other expensive drivetrain components. For the cost of one small washer, it is valuable protection against a much larger repair.
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$6.86
