# Clutch not engaging on Stihl HS81R Hedge Trimmer



## MattG

Hi folks,

I have a one year old HS81R which has done scarcely more than 10 hours work. Decided to start it up this evening to give it a run over winter and it started fine but the blades won't move at all. There *may* have been a slight click noise when I first started it, don't know if this indicates something?

I left it to warm up and gave it full revs, but the blades still wouldn't budge. The blades have been greased as needed in the past so it's not likely that they will have got stuck due to lack of lubrication. I rotated the handle to make sure that it wasn't getting confused about something not being in place (had encountered a similar thing on another model which stopped the blades from moving due to a safety feature if the handle was not locked in position).

Wondered if there was some part which is know for breaking easily (even in a fairly new machine with few hours work done)?

Any help greatly appreciated!

Matt


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## sawfun

It sounds like some kind of weak sacrificial piece broke. Either look up the schematic or pull the cover and see. I know you can replace the blades so I might start by taking them off and checking what connects them. I kinda doubt the clutch is bad. I have a 30" HS81R that I bought used. It had only been used lightly once. I had a buddy use his Stihl tool to bypass the limiter caps and richen it, as it was so lean with the factory setting as rich as it would go, that it would stall out and was way down in power. I love it now though.


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## Saw Dr.

I have seen the clutch hub shear on one of those. Stihl warrantied it. Going to require a bit of disassembly if that is the issue.


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## MattG

I fixed this in the end, it was just that the blades had jammed up over the winter. After taking off the bottom I managed to play with the conrod mechanism and work them free. It's all good now. Thanks.


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## MattG

Hey sawfun.

You said your hs81 was lean... Did it seem to hesistate when you gas it after a period of idle? Sometimes mine does if it's not really hot. Wondered if mine was lean too.


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## sawfun

Yes it did hesitate and sometimes die. The limiters hot repositioned so that proper adjustment was possible. I ran 50:1 non ethanol gas with Stihl ultra. I hated the machine till it was set richer. Now I love it, way more power.


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## MattG

Right. I thought it was my L screw at first. Now I read what you say, I'll have a play with the H screw when I next use it. Perhaps remove the limiter if ness.


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## sawfun

I had a friend with a special Stihl tool adjust the L and H side. This tool makes removing or modifying the limiters unnecessary. Both sides needed to richened just a slight amount.


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## MattG

Cool, thanks.


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