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Stihl BG85, restringing starter rope

Discussion in 'Mechanic and Repair' started by Roger, Nov 23, 2005.

  1. Roger

    Roger LawnSite Fanatic
    Messages: 5,938

    Perhaps this has been discussed before .... I have restrung recoil starters for various small engines, but I always feel I'm missing something. I understand the procedure, but one part always has me feeling like I should be doing it differently.

    How do you real mechanics hold the take-up spool while removing the old rope and threading in the new rope?

    I pull out all the rope, then take various means to hold the spool while under tension. That is the question -- the "various means." I usually find some cobbled up way to put a large clamp around the shroud, with one end of the clamp on one side of the spool. I feel that I'm going to break the spool by putting a force on one side. I keep looking for some hole or block to put a screwdriver through to keep the spool from spinning out of control, but never find one.

    I found my blower rope shredded, at least the outside cover, this afternoon. When the snow kept falling and leave kept getting wetter and wetter, we finally quit working. I got some rope and successfully got the new rope installed. But, again, I felt like there "must be a better way." I have a couple of other engines I want to restring during off-season PM, so am looking ahead a couple of weeks.

    Having the time, and having the cover off, I did the off-season PM right then and there (clean out exhaust, new plug, cleaned up, etc). This is one item I will not have to address in a couple of weeks when I go through all the tools. We only have about 15 cleanups and mowings yet to do.
  2. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,292

    I am not a real mechanic but I have put new ropes in many different pieces of equipment. The way you did it is okay, just get a metal c-clamp to hold the pulley. The other way is to cut the cord and allow the spring to unwind. Then with it unwound thread the rope through the case opening into the pulley hole and make the knot.. Next take a piece of wire and pull the rope up between the edge of the pulley and the case. Grasp the rope and wind up the pulley spring making sure you are going in the correct direction. Once it is wound you let go of the rope and get it back in the groove and the spring will pull the cord in. I am sure some will describe this better than I have and maybe have a picture.
  3. joe stihl

    joe stihl LawnSite Member
    Messages: 35

    You do not need to hold the rotor spring under tension to wind the new rope on. Do this:

    Take the spool off (pay attention to how the clip and pawl are in place) and put a new rope on it. Thread the rope through the cover and into the pull handle and tie. Wind the rope onto the spool.

    Put the spool back into the cover so it engages the spring. Put the pawl and clip back on. There is no tension on the spring.

    Reach into the cover and grap the rope between the spool and cover, pulling up a couple of inches of slack. Hold it next to the spool and turn the spool backwards . Some spools have a notch cut in them to hold the rope in place on the spool. The more turns you make the tighter the spring.

    Release the rope slowly so that it doesn't pop off the spool and you are done.

    Hope this makes sense.

    Once you do it, you will see how easy it works.
  4. Lawn Masters

    Lawn Masters LawnSite Senior Member
    Messages: 850


    In my experience, even when the spring is unwound, there is still tension on it as long as it is inside the case. you've seen how much larger those springs are if they're outside the recoil housing.

    The best trick I've found, is to simply let the old rope go, then feed it in through the pulley, pull it through to the hole in the recoil cover, then put the handle on it, after tying off both ends, and then find the notch in the pulley, use that to rotate it the proper direction, and get the correct tension on the spring.
  5. joe stihl

    joe stihl LawnSite Member
    Messages: 35

    Excuse me. There is no spring tension against the spool when the spool is installed. You said the same thing I did.
  6. mtdman

    mtdman LawnSite Gold Member
    Messages: 3,143

    Bingo. This is exactly how it's done.
  7. Roger

    Roger LawnSite Fanatic
    Messages: 5,938

    Joe ... mtd ... Does this method imply the torsion spring will only grab to the spool in one direction? By that question, does the spring only engage the spool when taking up the rope, but not when letting it out?

    I understand your instructions regarding taking off the spool, and putting the new rope onto the spool (stringing through a hole in the spool and tying it off). And, I follow the part of threading through the cover and putting it through the handle and tying off outside the handle.

    Now, putting the spool back on the post with the spring clip seems easy to follow, and I understand there is no tension on the spring.

    But, grabbing (I think you meant grab, not grap -- right?) the rope and pulling out a short length, then turning the spool backwards has me puzzled. Returning to me first question, does the backward turning of the spool mean the spring is not engaged with the spool, but will engage when tension is created? Is the "hook and socket" (?) arrangement a one-way construct, that is, it will engage in only one direction?

    Perhaps this is one of those "have to do it to understand, but hard to explain" matters. I have a couple more to restring soon, so will give it a try.

    Thanks for the instructions.
  8. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Rotate the spool counter-clock wise and you will feel the spring tension if the spool hooks the spring properly. I will Never remove a spool just to install a new rope, It's a waist of time to me. I use the method ed2hess outlined and it works great.
  9. Jim Buessing

    Jim Buessing LawnSite Member
    Messages: 53

    Joe Stihl has the proper way of spooling 2-cycle starters. That is the reason for the notch in the starter drum so you can wind it. YOu wind it until it stops then back of 1 full turn. This keeps proper tension on the rope and also ensures that you will not pull the rope to end of the spring when starting and break the spring.
  10. Lawn Masters

    Lawn Masters LawnSite Senior Member
    Messages: 850

    I meant something a bit different than you I think then. sorry I misunderstood what you were saying.

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