NWP Oil Pump Worm Gear for 064, 066, MS640, MS650, MS660 Chainsaws (Replaces 1122 640 7105)

NWP worm gears are an economical replacement option for your Stihl chainsaws. Worm gears (also known as pinion gears) are one of those wear items that get little attention until they quit working. Like all moving parts, they will eventually give out with prolonged use and need to be replaced, especially when running low quality bar oil or used motor oil. We recommend having a couple of spares around.