Stihl trimmer problems

[lawnman91375]

Hello, I need some help with my Stihl FS-90R trimmer. I just cut my grass for the first time the other day and noticed that the trimmer head is not stopping after throttle release. I adjusted the carb and no luck. The only thing I can think of is a bad clutch. Do you have to replace the whole clutch Assembly or can it be cleaned? What other things could it be?

 

[ILENGINE]

Could be either a broken spring on the centrifical clutch, or the clutch drum is sticking to the engine crankshaft.

 

[Ric]

Hello, I need some help with my Stihl FS-90R trimmer. I just cut my grass for the first time the other day and noticed that the trimmer head is not stopping after throttle release. I adjusted the carb and no luck. The only thing I can think of is a bad clutch. Do you have to replace the whole clutch Assembly or can it be cleaned? What other things could it be?

You should be able to back out the idle adjustment (LA) until the trimmer head comes to the point of stopping. The other thing that could cause the problem would be the spark arresting screen needs cleaning. Your High and low speed screws should be back out 3/4 of a turn at least that's the factory settings.

 

[pugaltitude]

Things to try 1st.
Is your revs going down when adjusting your idle screw?
If no is your cable wrongly adjusted or sticking?

If its clutch then yes usually a replacement of clutchshoes is required but superglue can stick the shoes back on but not advisable.

 

[lawnman91375]

I just tore it down and there is some rust on the clutch shoes. The spring is fine. The spark arrestor screen is fine but I cleaned it anyway. I believe the culprit is rusty shoes. Can I clean them with an abrasive like very fine sandpaper or emery cloth?