In this video, we show you how to change an anti-vibration spring on a Stihl TS420 disc cutter.

Health & Safety Warning - Please ensure that you have safely prepared the machine and workspace. If you are unsure about any aspect of the task please seek professional advice.

Transcript

Today, we're going to change the Anti vibration or AV Spring on a Stihl TS420 cut off saw. First of all, use a torx spanner to remove the screw that secures the water connector from the underside of the machine. This will provide better access to the recoil. Next, use a 19mm Hex Socket Spanner, turning it anti-clockwise to loosen the tension of the belt. Once this is done, use a 13mm Hex Socket Spanner to loosen the three nuts that secure the recoil assembly. Then revisit each nut and completely remove them, freeing the recoil from the machine. Using the torx spanner, remove the screw that secures the nose guard to the arm. Once the nose guard is off, use the 19mm Hex Socket Spanner, turning it anti-clockwise to further loosen the tension of the belt.Completely remove the front of the saw to free the belt. Using the Torx Spanner remove the screw which holds the AV Spring Clamp in place. Once again use the Torx Spanner to remove the three screws which hold the Muffler in place. Remove the top cover to provide access later on. Using the torx spanner remove the four screws that secure the air filter cover located at the back of the machine. Now remove the paper and gauze filters. To remove the shroud, use the torx spanner to remove the two screws located near the fuel cap. Disconnect the control rods. You may also want to remove the plug cover to make it easier to remove. You can now remove the AV Spring by removing the torx screw on the inside of the spring. Locate your new AV Spring in position and hand tighten the screw in place, then return to tighten with the Torx Spanner. Locate and screw the clamp back in place to fix the Spring in position. Secure the Muffler in place using the 3 screws. Reconnect the control rods back into place. Now that's complete you can relocate the shroud, make sure it is seated correctly and everything is contained and then secure with the torx screws. Then simply replace the gauze air filter, the genuine gauze has a tab to indicate the correct way to fit it. Replace the paper air filter in, with the mould surrounding the ducts and the filter positioned over the gauze filter. Place the casing back over the filters ensuring it is seated correctly. Make sure the screws secure the plastic cover without overtightening. Relocate the top cover and screw it back on using the torx spanner. To fit the belt locate it over the clutch making sure it is sitting in the grooves correctly to prevent damage to the belt. Then feed the belt back through the arm, relocating the arm back in to position around the studs. Slowly turning the pulley will help you easily feed the belt back around the pulley. Make sure the blade turns with a smooth motion. Relocate the casing onto the arm and use the torx spanner to fix this in place. Make sure the screw is secure without overtightening it, as the casing is only plastic. Locate the recoil assembly onto the machine, loosely turn each nut a few times. Then return to tighten each nut with the 13mm spanner, again, be careful not to split the plastic when tightening. Then re-tension of the belt using the 19mm Hex Socket Spanner. Don't forget to fix the water connector back into place under the machine using the torx spanner. That's how you change the AV Spring on the Stihl TS420. All the parts & tools needed for this task are listed in the description below.

Parts

Parts and tools included in the TS420 disc cutter how-to video.

• Anti Vibration Spring - 4238 790 8301
• Handlebar Support - 4238 791 1900
• Handlebar Support Clamp - 4238 791 0900
• Pan Head Self-Tapping Screw D5 x 45 - 9075 478 4190
• Pan Head Screw P6 x 19 - 9074 478 4425
• Blue Nitrile Disposable Gloves - Varied Sizes
• Genuine Torx Wrench/Plug Spanner - 4224 890 3400
• Non Genuine Torx Wrench/Plug Spanner - 410 250