Stihl FS85 clutch

Discussion in 'Lawn Mowing' started by Roger, Dec 5, 2004.

  1. Roger

    Roger LawnSite Fanatic
    Posts: 5,923

    I had a nice trimming opportunity to do "when you have some time when the season winds down." I knew the job would require two full work days, over 50 burning bushes, 25 Canadian Hemlocks to shear, plus some other bushes.

    The weather was cold (35-38) on Friday, but I decided to start. I used my Stihl HS-80 nearly all day, getting most of the burning bushes trimmed down. We made good progress despite the heavy dress and cold temps. The trimmer worked flawlessly.

    On Saturday morning, the temps were colder, about 25 at 8:00, but forecast ed to warm up. I use my Stihl FS85 string trimmer with a zero-degree hedge clipper attachment to shear the Canadian Hemlock (9-12 ft high, 7-8 feet across at the bottom).

    I mounted the attachment on the FS85, but the cold gear case made blade movement difficult. The engine was revving, but little blade movement. I realized I was slipping the centrifugal clutch. I took the unit inside the house, running hot water over the gear case to warm it. When I took it outside, the engine was able to drive the clipper pretty well. However, I could tell the engine was really laboring to drive the blades. I used it a few times this Summer, and it worked fine.

    When getting to the job site, I fired it up right away, hoping the gear case still had some heat (normally, it runs quite warm during service). It worked, but I always felt the operation was a bit erratic. The engine was under heavy load, not from the shearing operation, but just to keep the blades moving when the temps were cold. I trimmed about 20 of the Canadian Hemlocks, running through 3 or 4 tanks of fuel.

    But, I'm concerned I may have damaged the clutch. Is there any way of knowing? At the end of the day, when I got home, I changed the clipper attachment back to the string trimmer. It fired, and run well. The trimmer is about four years old, trimming out 1,000 to 1,200 lawns per season. I don't want to start a new season, if I have a marginal clutch.

    Any way to know if it is OK, short of pulling it apart.

    P.S. The hedge clipper attachment for the FS85 is a huge time/energy saver on these jobs. It has paid for itself several times over in the past couple of years. I only needed a ladder on one tree to finish out the top, the rest of the work was all done from the ground. I needed about 15 minutes per tree, including all cleanup.
  2. specialtylc

    specialtylc LawnSite Bronze Member
    Posts: 1,656

    It sounds to me like you have the blades adjusted too tight or the blades are gummed up. I have never had any problems in cold weather with my Stihl hedge trimmers. WD-40 sprayed on the blades really helps to clean off the junk and makes them run smoother.
  3. DennisF

    DennisF LawnSite Bronze Member
    from Florida
    Posts: 1,381

    The clutch is one of the toughest components on the tool, so I don't think you did it any harm. Even if you did, just run it until the trimmer head begins to slip when you're trimming tall grass, then change out the clutch. Changing the clutch is no big deal...about a 30 minute fix if you're mechanically inclined.

    By the way...hang on to that FS-85. They're getting hard to come by.
  4. joeboy4

    joeboy4 LawnSite Member
    Posts: 29

    I would recommend Pam cooking spray instead of wd-40 on the blades. wd can cause the hedges to turn brown.
  5. sawman65

    sawman65 LawnSite Senior Member
    Posts: 751

    that clutch has a lifetime warranty if you can break it sthil will fix it.if you have a copy of the warranty form.the dealer you got it from should have one
    they are supposed to any way.
    now if the clutch springs go bad,say from to much heat that is your dime
    at least they are easy to replace.and as was said hold on to that 85 they are
    almost gone the 80 will still be around but not the 85
  6. rgjlawn

    rgjlawn LawnSite Member
    from midwest
    Posts: 84

    i think they have a recall on fs85. check with your dealer.
  7. 65hoss

    65hoss LawnSite Fanatic
    Posts: 6,360

    Take the attachment back off and then re-install it. Sounds like you may not have got it completely on. The shaft could be in just enough to barely grab.
  8. sawman65

    sawman65 LawnSite Senior Member
    Posts: 751

    the recall is on the 55 not the 85
  9. Travis Followell

    Travis Followell LawnSite Silver Member
    from KY
    Posts: 2,207

    Whats the recall about?
  10. crawdad

    crawdad LawnSite Bronze Member
    Posts: 1,939

    Why? It's a good machine, why stop making it???

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