Stihl fs85r clutch slipping Need ADVICE please

Discussion in 'Mechanic and Repair' started by S man, Mar 5, 2008.

  1. S man

    S man LawnSite Gold Member
    Messages: 3,562

    I was going to post this in Roger's thread about his stihl fs85 having a clutch problem and resolved it by putting in new springs, but I decided to start a new thread about my stihl fs85 having the clutch slipping and making a squeaky different sound from the usual bell tingling sound.

    "I know this is an old thread but one of my fs85s is having a problem with the clutch and sounds like the spring prob you were having. But mine when warm will have the head spinning in idle sometimes. And it makes a squeaky metal sound without the tinging stihl clutch sound. When I hear the normal stihl tinging bell sound the head doesn't spin in idle. It seems like the clutch is messed up with these symtoms right? The trimmer is only a year old and is run without the guard and my dad was running it most of the time with extra string and not giving it full throttle giving it a bell sounding rough sound. Then after he was running it it started making the metal squeaky sound and having the head spin when at idle or when turned upside down for edging. Is this the spring problem or something else with my trimmer? It is at the shop again for repair for the problem. The first time I brought it in they took two weeks to look at it and then said it was fine and didn't fix anything. This time I want this legitimate problem fixed. It has to be warmed before it acts weird. Any ideas of the slipping clutch?"
  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    If the head is spinning it ain't the clutch...
    Because if the clutch was slipping the head wouldn't spin...

    When's the last time you greased up the gear box?
    Down by the head, there's a small bolt on the side...
    You're supposed to grease this at least once / year, it usually doesn't take much but if they run dry...

    Worst case you probably need a new head, but I had this problem 6 years ago on an fs-85 and the head is in use today (thou the engine was at fault, loss of compression).

    So I'd check compression also.
  3. S man

    S man LawnSite Gold Member
    Messages: 3,562

    I thought if the clutch was slipping the head would spin?? It off and on makes a metal queaky sound coming from the clutch and and head spins without triggering it. Is it really the head??? The sound is coming from the clutch.
  4. Landrus2

    Landrus2 LawnSite Fanatic
    Messages: 5,020

    you need to replace the clutch assy.:waving:
  5. S man

    S man LawnSite Gold Member
    Messages: 3,562

    Isn't that stuff under warranty for life? I checked my manual and it is so the dealer will fix it. What gets me is why this happened the trimmer is only a year old. and I don't use it all the time either. I thought stihl had the best clutches? Never had a problem like this with redmax. Which I will be getting a 2601s soon.
  6. Roger

    Roger LawnSite Fanatic
    Messages: 5,941

    Perhaps this is a menu for excessive load on the clutch. Having extra string beyond what the guard would allow requires extra power. And, running at partial throttle means the driving dogs don't have the centrifugal force to engage as fully as at full throttle. Each of these factor could create a problem, and the combination can make the matter even worse.
  7. Landrus2

    Landrus2 LawnSite Fanatic
    Messages: 5,020

    Redmax good choice.:waving:
  8. S man

    S man LawnSite Gold Member
    Messages: 3,562

    It seems like stihls clutches are worse than echo and redmax because I have ran both redmax and echo without guards and didn't have this problem with the head spinnin like crazy after one year of use. Also because it does have to be run at full throttle because you have to get over that clutch sound that makes some vibration at first. They say to run stihls at full throttle but sometimes when my dad uses the trimmers or have employees use them they don't run the units at full throttle at all times, so I'm suppossed to have problems in a year? the problem is actually worse with the guard on and short string running. My dad used the redmax at half throttle and never had the problems and clutch issues the stihl is having. We'll have to see what the dealer says.

    I know I regreted selling my older one.
  9. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,378

    I have run both Echo and Stihl and I have never had to replace a stihl clutch although I only ran 3, but one was an 85. Running at low rpm and taking the guard off is not going to take out those clutches unless you ran it a long time in a failed mode. The spring that holds the clutch pads from rubbing at low rpm may have broke. This would account for head spinning at low rpm. And if you kept using the unit for a long time it may have damaged something.
  10. S man

    S man LawnSite Gold Member
    Messages: 3,562

    Thank you mr. Hess just the answer I needed. It sounds like the springs are the problem. Are they covered like the rest of the clutch under warranty?

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