fs100 vibration.

[jamesd]

If it was that, would it cause the hedge cutter head itself to wear more rapidly? as this year one has already had the bearings go!

[GardenKit]

You mean items 21 and 22 in this image?

https://www.google.co.uk/search?q=4137+711+7300&client=firefox-a&hs=XYN&rls=org.mozilla:en-GB:official&source=lnms&tbm=isch&sa=X&ei=ajjQUonHCNLT7Aabo4HoCw&ved=0CAkQ_AUoAQ&biw=1280&bih=598#facrc=_&imgdii=_&imgrc=Oqgqk2CswfuwbM%253A%3Bb5ZQYwq9CjQ-fM%3Bhttp%253A%252F%252Fwww.magic-parts.co.uk%252Facatalog%252FFS120_2.gif%3Bhttp%253A%252F%252Fwww.magic-parts.co.uk%252Facatalog%252FStihl-FS120.php%3B540%3B453

yes, thats the liner, but my money is on the clutch drum bearing.

[jamesd]

You couldn't point me in the direction of which bearing you think it is so i know what i'm looking for please?

https://www.j-thomas.com/Portal.aspx?CN=332D35A4B22A&MODELID=B11AC53F0A29

[GardenKit]

I can't open the pics on your link.

 

But you will find the clutch drum and bearing in the cone shaped bit that joins the shaft to the engine.

If you take the drive tube off first, then the cone shaped bit, you will find the clutch drum inside. If its firm and spinning freely all is well. If its flopping around or very noisy when it spins, it needs replacing.

[jamesd]

https://www.google.co.uk/search?q=stihl+fs+100+clutch+bearing&client=firefox-a&hs=lfN&rls=org.mozilla:en-GB:official&source=lnms&tbm=isch&sa=X&ei=KjrQUq_GDciN7QbNm4DwCg&ved=0CAkQ_AUoAQ&biw=1280&bih=598#facrc=_&imgdii=_&imgrc=1DUZEHcJU7rolM%253A%3B8bFt8nRiRmSvRM%3Bhttps%253A%252F%252Fwww.j-thomas.com%252Fproducts%252Fschematic%252FStihl_FS90R-Trimmer_engine_parts.gif%3Bhttps%253A%252F%252Fwww.j-thomas.com%252FPortal.aspx%253FCN%253D332D35A4B22A%2526MODELID%253DB11AC53F0A29%3B2818%3B3457

This one work for you?