How to Put More Torque on My 300EX

Improving the torque output on a Honda 300EX quad will result in faster starts and more power in the low-end rpm. As an all purpose four-stroke ATV, the 300EX bridges the gap between the FourTrax utility quad and the TRX 450R race quad. With only 299 cc, the 300EX lacks the brute low-end torque of the TRX 400X, 450R and 700XX. However, with a replacement of the rear sprocket, you can increase the torque of the TRX 300EX.

Things You'll Need

  • Socket wrench set
  • Aftermarket sprocket w/ increased tooth count
  • Hydraulic jack
  • Chain break tool
  • Hammer
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Instructions

    • 1

      Locate the rear sprocket on the rear axle and count the number of teeth the stock sprocket has. Order a sprocket with one or more extra teeth. As the number of teeth increases, the diameter of the sprocket increases, providing more surface area for the drive chain to connect and turn the rear axle. In turn, your low-end torque/acceleration will improve.

    • 2

      Loosen the lug nuts on the rear wheels.

    • 3

      Place a jack under the center of the rear axle and jack the quad up until the rear wheels leave the ground. Then, remove the lug nuts and pull the tires off the axle.

    • 4

      Use the chain break tool to separate the master link on the drive chain, removing it from the sprocket. The master link is often denoted with an "M" or colored link. It also looks different than the other chain links.

    • 5

      Remove the three sprocket attachment bolts using a socket wrench and slide the sprocket off the axle.

    • 6

      Attach the larger sprocket and tighten the sprocket bolts to the sprocket hub.

    • 7

      String the chain over the sprocket and reattach the master link using a hammer and improvised backing plate.

    • 8

      Reattach the wheels and hand tighten the lug nuts. Tighten the lug nuts fully with a socket or impact wrench.