Outdoor Power Equipment and Small Engines - Stihl FS81 weed eater

Howdy folks. I have a Stihl FS81 weed eater that I'm trying to put a metal cutting blade on in place of the string. I've got a lot of well established Himalayan blackberry briers to remove and the string just isn't cutting it. I can't figure out how to remove the string head. There is a nut in the center of it that I thought would come off, but it doesn't. When imobilizing the string head, the nut will turn either direction but not come off. Any one out there know how to make the swap?

The head is mounted with a left hand thread, so you have to turn it clockwise to get it off. The gear box needs to be locked with a small pin, punch etc. to prevent it from turning while you are unscrewing the the and when you tighten the holding hardware for the blade. Here is a link to an owners manual that should show you how to switch out your cutting attacments.

http://www.stihlusa.com/stihl_ownersmanuals/FS81_86_106_Manual.pdf

30yearTech,

Thank you very much, that was what I needed to know. The manual had pictures that helped also. The briars are gone, the little woman is happy, and things are lookin' up. Have a great day.