How does a KYMCO ATV CVT Work?

Today at Cyclepedia Press LLC, we are about to dive into the CVT of a 2013 KYMCO MXU 700i ATV. Many of our online service manuals for scooters, ATVs, and Side-by-Sides feature CVT transmissions so while there are some differences between these various applications the theory is the same. For those curious on how these simple but effective transmissions work we shot a demonstration video of a CVT in action. Remember to never operate a CVT without the cover in place. If you do remove the cover always be sure to inspect and clean a CVT that has been contaminated.

The continuously variable transmission, or CVT, is a common component in the powersports industry. This is the transmission that has given scooters and snowmobiles the ability to be gas and go for decades. The CVT has also found a home in ATVs and utility vehicles where a simple automatic transmission is desired.

The vast majority of CVTs, on the road and off, are of the variable diameter pulley type. This consists of two sets of pulleys connected by a stiff rubber belt.

The inside of the pulley faces form a V-shape. Each pulley has one fixed face and one movable face. The gear ratio is changed by moving the faces of one pulley closer together and faces of the other pulley farther apart. Due to the V-shaped cross section of the belt, this causes the belt to ride higher on one pulley and lower on the other. This changes the effective diameters of the pulleys, which in turn changes the ratio. The distance between the pulleys does not change, and neither does the length of the belt, so changing the ratio means both pulleys must be adjusted (one bigger, the other smaller) simultaneously in order to maintain the proper amount of tension on the belt.

CYCLEPEDIA Online Service Guides and Repair Manuals that feature CVTs:

• Honda CH50 Metropolitan
  
• Honda CN250 Helix
• Honda NPS50 Ruckus
• ATV Belt Reset Guide
• Kawasaki KVF650 and KVF700 Prairie and Brute Force
• KYMCO Downtown 200i and 300i
• KYMCO Mongoose 70 and 90
• KYMCO MAXXER 450i and MXU 450i
• KYMCO People GT 200i and 300i
• KYMCO UXV500 and 500i
• KYMCO Xciting 500 Ri and Xciting 500 Ri ABS
• Polaris 50 and 90 Youth ATVs
• Suzuki AN400 Burgman
• Suzuki AN650 Burgman
• Suzuki LT-80 Quad Runner and Quadsport
• Suzuki LT-V700F TwinPeaks