Picture of Rescue for a Weed Whacker
This is a scanned photo of my weed trimmer. The centrifugal clutch inside the clutch housing (yellow square) came loose and chewed the plastic clutch housing to pieces so that the engine hung loosely from the throttle cable. I checked into getting a new clutch housing, but encountered only dead ends.

(The reason the clutch came loose was that I tried to open the machine so I could tighten up the starter cord. Doing that compromised the clutch's retainer. Although I tried to improvise something, it did not hold.)
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Step 1: A better clutch retainer

Picture of A better clutch retainer
This is an exploded drawing from the weed trimmer's manual. I added the colored items. The first step was to make certain the clutch bell (larger cylinder between the green and yellow boxes, right most of the three lines from #11) could not slide forward from the centrifugal weights assembly (#10) on the clutch bearing (smaller cylinder left of the green box) and the shaft connected to the engine (black cylinder portion in the green box). I drilled a hole (red circle) through the clutch bell assembly and just a little into the black shaft in the green box. I threaded the red hole for a set screw. I locked the setscrew in place with a tack weld. I filed the weld at the setscrew smooth so it does not rise above the surface of the clutch bell's shaft portion. If I ever need to remove the clutch, I will drill out the setscrew tack weld.

Step 2: Where to mount an improvised clutch housing

Picture of Where to mount an improvised clutch housing
This is the same graphic from the previous step. Note the four holes in #5 (starter housing shroud) that receive screws #8 (follow the dotted line running through #7). These were used to mount an improvised clutch housing.

Step 3: Clutch housing mounting tabs

Picture of Clutch housing mounting tabs
When I needed to make this repair, I was much involved at a construction site. Pictured is an electrical panel. Notice the gray knockouts between the breakers. I gathered four of these from scrap materials on the ground. I bent each into an "L" shape. See the next step.
dq32211 year ago
Rather impressive article with some good points! I think all these information are very helpful for rapire weed whacker or outdoor power tools.
Goodluck5 years ago
Nice improvisation with the materials at hand. Even though you've not yet been injured and can see no path to injury, it could still happen. It seems that your shaping pvc in the microwave instructable could provide a good method for building a guard if you so desire.

A note on step 7... if you cut the block of wood in half, screw it back together and then drill the hole, the resulting hole is round and you end up with no visible kerf when installed. Of course you'd need to drill a hole slightly smaller than the boom to achieve a good 'clamp' on the boom.

I know you're unlikely to modify this as you've been using it for "more than ten years", but just some ideas for others that may see this and think "I could use that idea to solve my similar problem."
Phil B (author)  Goodluck5 years ago
Thanks for looking at various Instructables I have done.  Someone would need foolishly to poke his fingers into the clutch area to be injured by it, and then it would likely be a burn or a small cut from the edge of the clutch.  As soon as pressure on the throttle trigger is released, the exposed portion of the clutch stops by itself.  There would be more danger of injury from the whirling string when in normal use or from touching the hot muffler on the engine. 
whats that
will it work for a large go kart
rimar20006 years ago
Bien, Phil! (¿alguien sabe cómo traducir al inglés la expresión "¡este es mi pollo!"?) Well, Phil! (knows anyone how to translate to English the Spanish expression "¡este es mi pollo!"?)
Phil B (author)  rimar20006 years ago
Rimar, Thank you for your comment. I did some searches on "¡este es mi pollo!" and found nothing other than a literal translation of the words, namely, "That is my chicken." But, I am sure it is an idiom with meaning beyond the bare words. I am guessing it would be something like, "It is my cup of tea." meaning "It fits my interests." Correct me, if I am wrong.
I suppose the phrase comes from Cockfighting, but I'm not sure. The meaning is "that is the person (or chicken) for whom I have bet all my money" or so. They say it as a compliment when a friend or relative achieves something important. It is a way of "taking" the achieving of the other. I suppose that English should have a similar saying, that possibly translated into Spanish does not make much sense.
Phil B (author)  rimar20006 years ago
Thanks, Rimar. I suppose in English we would say, "I am putting my money on him." or, when referring to another, "She is hitching her wagon to him."
yokozuna Phil B6 years ago
There is an English expression similar that states "Don't put all your eggs in one basket" meaning don't bet everything on one idea. While they don't say the same thing exactly, it seems like too much of a coincidence to just be random.
Thanks, yokozuma, but the idea of the expression is different.