Chain Idler Pulley Replacement

Parts Needed

  • 1 x PN 1024 Chain Idler Pulley
  • 1 x PN 1248  ¼-20 x ¾” SS screw (not always needed)


Tools Needed

  • Phillips Screwdriver
  • T-27 6-Lobe driver or 5/32” Hex L-key
  • 9/16” wrench


  1. Loosen the screw that clamps the outlet perf together. This screw will be located under one of the bosses of the flywheel cover.

    Loosen the screws on the front of the perf that clamp it down

  2. Loosen and remove the four screws that attach the flywheel cover.

  3. Remove the flywheel cover and outlet perf and set aside.

  4. Hold the flywheel with one hand while loosening the axle nut with a wrench. The clutch in the flywheel hub will keep the axle from turning.

  5. Grab the flywheel with two hands and pull away from the body of the machine to remove.

    remove the flywheel from the body of the machine

  6. Slide the handle through the chain guide to relieve tension on the chain.
  7. Remove the screw that’s located in front of the generator housing. Removing this screw will release the Anti-Skip Anti-Throw (ASAT) device. Machines made before 9/7/18 will not have an ASAT device and will not have this screw.

    Removing screw in front of generator housing

  8. Stand the machine on end so that the foot stretchers are up. Remove the plastic return mechanism cover by sliding it up and out between the foot stretchers.
  9. Flip the machine over so that the bottom of the machine is facing up.
  10. Remove the ASAT device from the axle. Note the orientation of the ASAT device prior to removing it from the machine.
  11. Remove the axle screw from the flywheel side of the axle.
  12. While holding the axle in place, remove the screw from the non-flywheel side of the machine. If the axle spins with the screw, insert an unpatched screw on the flywheel side and tighten. This will prevent the axle from spinning when loosening the non-flywheel side screw. Then remove the unpatched flywheel side screw.
  13. Carefully pull the axle, chain, and pulley out of the machine.
  14. Replace the old pulley with the new one. If the machine does not have an ASAT device, confirm that there is a spacer on either side of the pulley before reinstalling the axle.
  15. Insert the axle, chain, and pulley. Confirm that the axle will not interfere with the movement of the shock cord.
  16. Thread the axle screws into both sides of the axle and tighten the screws.
  17. Attach the ASAT to the axle.
  18. Use one hand to hold the ASAT in place while securing it with a screw.
  19. Slide the handle through the chain guide while confirming that the chain is still routed properly around the chain idler pulley and sprocket.
  20. Flip the machine right-side-up, so that it’s resting on the front foot and foot stretchers. Slide the flywheel onto the axle.
  21. Confirm that the handle is resting against the chain guide. The handle and chain will keep the axle from spinning. Thread the axle nut onto the flywheel. Tighten the nut with the wrench.
  22. Attach the flywheel cover by threading all four screws into the nuts. Leave all four screws loose.
  23. Lace the outlet perf under the bosses of the flywheel cover.
  24. Attach the two ends of the outlet perf. Move the outlet perf so that the connectors are hidden under one of the flywheel housing bosses.
  25. Tighten the outlet perf connector screw.
  26. Tighten the four screws on the flywheel cover.