Stens New Trimmer Head Bump Knob 385-876 Compatible with Stihl FS36, 40, 55, 66, 72, 76, 81, 86, 96 and 106 4002 710 4000, 4004 710 4000

NA

This works perfectly on my STIHL FS 40C with a minor modification. The new threads on the new nut are too big.You must remove the nut from the old one.I did this indoors so I didn't lose anything. You may want to wear safety glasses in case the clip snaps out.I used a small slotted screwdriver to get the clip out that holds the nut. Once you get the nut out, remove the clip holding the new nut and replace it with the old nut.Again, I suggest doing this indoors in case the clip flies out. You will need that new clip to hold the nut in.Credit goes to "aaprime" for his excellent review!

Fit great once I replaced the nut with the old bump head nut

This knob that was supposed to fit a Stihl FS40, came with the wrong size hex nut in it. I simply had to remove the snap ring and put my old nut in the knob. Not everyone would have snap ring pliers to easily do this replacement. Also, luckily I saved the original nut. It's metric which would have been another headache. This is the reason for the 4 stars.

This but in the head is not the right size for a Stihl FS 40C. Save the nut from your original bump head. The outside dimension of the nuts is the same. The difference is the diameter of the threads inside the but are different. There is a metal clip holding the nuts in the bump head. Remove the clip with a pair of needle nose pliers or a small flat head screw driver. Needle nose pliers or lock pliers are best since there is a good chance the clip will pop out and go flying. You don't want to lose the clip. The old nut may need not come out that easily, use pliers, bang it on the concrete floor or thread a bold into it to pull it out. Put the old nut into the new bump head and replace the metal clip. You are good to go.

Simple repair for an old Stihl trimmer.

Works just like the original

Does not fit older model even tho on the website it says it does.

Worked exactly as expected - would but again