Muffler loading up

Discussion in 'Lawn Mowing' started by Jerrys Lawn Service, Sep 8, 2000.

  1. Jerrys Lawn Service

    Jerrys Lawn Service LawnSite Member
    Messages: 155

    I've been having some trouble with my Stihl FS 80 trimmer
    the muffler keeps clogging up with oil residue I am using
    the correct mix 50-1, but it still is bogging down and whats
    even more crazy is the hotter the temp is outside the worse
    it becomes! I've taken it to my local dealer and was told
    that I wasn't running it hard enough, he said wide open all
    the time, I told him that this wasn't possible all the time
    because of people, cars, houses, WINDOWS! What do you guys think? I talked to another landscaper and he said he's
    having the same problem.

    Good Luck to all
  2. bob

    bob LawnSite Platinum Member
    from DE
    Messages: 4,262

    Did you take the spark arrester screen off?

    BUSHMASTER LawnSite Senior Member
    Messages: 519

    Question are you using the spark arsetor?if so get rid of it unless are are in a fire hazard area.if not i probally would look at the carb that were the mix enters the engine,
    it may be nasty inside allowing more fuel the need or adjusted for,if thats it just clean it and rebuld it.This would probally explain the lack of rpms these are my thoughts anyway.
  4. LoneStarLawn

    LoneStarLawn LawnSite Bronze Member
    Messages: 1,415

    Spark arrestor!!! Take it off...
  5. Jerrys Lawn Service

    Jerrys Lawn Service LawnSite Member
    Messages: 155

    Spark Arester is already gone and problem didn't go away,
    we did punch some holes in the ports of the muffler with a screwdriver, this did help somewhat.
  6. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Messages: 4,830

    If it's not the spark arrester, it's carbon build up on the exhaust port. Take the muffler off and see if carbon has built up around the exhaust port, if so, clean it out and it will run full RPM's again, like when new. I clean the exhaust port opening each year on the string trimmers. You won't believe the difference. The Back Pack Blowers normally don't have this problem, since they are usually running wide open most of the time.
  7. bridges

    bridges LawnSite Member
    from RI
    Messages: 196

    I just bought the fs 80 last week and no promblems eith it yet.

    Hey eric thanks for the info. i had never done that to my echo's.

  8. MOW ED

    MOW ED LawnSite Fanatic
    Messages: 5,028

    Follow Stones advice as well as take the screen out. That heave petroleum based 2-cycle gums everything up and smells bad. You will soon change all of your 2 cycle to synthetic.
    I did years ago and havent had a problem.
    I even use it in the Lawnboy. The only problem is that now I get bit by mosquitos because I am not mowing in the blue cloud.

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