Chainsaw Repair

Y089000040. Around $40...

That tool is a set for all models. Less $ for model specific puller

To cool Adam. I never knew about the echo tools.

Pic I found on bay.  http://www.ebay.com/itm/91120-Y089000010-20-30-40-Echo-Worm-Gear-Installer-Tool-Set-/390640408992

Echo Special Service Tool - Tool Set replaces old part numbers Y089000010, Y089000020, Y089000030 and Y089000040  - 4 tools in one set - Complete with pusher tool , washers and 4 adapters to install worm gear on Echo Chainsaws:

Y089000010 used on CS-450 and smaller saws
Y089000020 used on  CS-510/520/530
Y089000030 used on CS-8000
Y089000040 used on CS-6700/670/680

For Worm Gear Puller, see # 89770819835