Help Needed With Weed Eater Motor

Discussion in '2-Stroke Engines' started by Jamie197235, May 24, 2008.

  1. Jamie197235

    Jamie197235 New Member

    Can a clutch be added to a weed eater motor? Or is a kill switch just as effective?

  2. miletwo

    miletwo Member

    I've got the same question myself but so far it's looking like "yes, but not without access to some machining tools" because you would need a way to extend the shaft of the motor a bit to accept a clutch. I'm working on just such a thing for my yardman ym400. I've pulled the center shaft off and I'm trying to find stock that will work to build a new center shaft that will extend out another inch and 1/2 then add a clutch from a chainsaw.

    Not sure how long it will take but let me konw if you come across anything.
  3. Addicted

    Addicted New Member

    All the trimmers i have ever seen have a centrifical clutch already on them,i have 4 i will be playing with shortly.
  4. Jamie197235

    Jamie197235 New Member

    I'm also using a yardman weed eater motor. It's 31cc. I was weed eating earlier with a weed eater brand weed eater and noticed when it was idling it was still spinning. Is this going to cause a problem if my yardman motor does this on my friction drive set-up?
  5. Addicted

    Addicted New Member

    Was it just idling too high?There is a clutch on them.
  6. eljefino

    eljefino Member

    Some of the cheap ones (walmart) have no clutches.
  7. BSA

    BSA Guest

    You could add a compression release valve, allowing you to turn the engine over without compression for just plain cycle-ing, and firing up the engine when needed. I think thats what wartime whizzers did.

  8. miletwo

    miletwo Member

    I've found that indeed the YardMan ym400 and similar small and cheap motors do not have a clutch on them. Also, be aware that finding parts for the cheapies is not so easy. I tried getting piston rings for mine and they only want to sell the complete piston with rings on to the tune of about $45 shipped. Better off buying another motor.

    I'm now looking at getting a similar sized but higher end motor liek a Ryobi or other with clutch already on it. These can be found on craigslist and eBay for around $40 and availability of parts is much higher.

  9. Mercurius

    Mercurius Member

    (I'm new, first post)

    So, no clutch means no friction drive bike. right?
  10. arceeguy

    arceeguy Active Member

    You can rig a mechanism to lift the engine off of the tire to allow it to idle.

    Since you are new here (so am I), I think the admins would like it if you posted in the "Introduce Yourself" forum.

    Good luck on your projects!
  11. spad4me

    spad4me Member

  12. Jamie197235

    Jamie197235 New Member

    Help Needed

    What is the easiest way to rig a mechanism to lift motor off tire?
  13. Jamie197235

    Jamie197235 New Member

    Another Question

    I'm also wondering what gear on bicycle I should use to pedal assist my friction drive set-up?
  14. miletwo

    miletwo Member

    That will probably depend upon how many gears you have. I would recommend trial and error as the best means for making this determination.
  15. arceeguy

    arceeguy Active Member

  16. victoreperez

    victoreperez New Member

    edger parts

    to lift your engine off your tire: go to a lawn motor repair facility...ask them for the part that the edger uses to lower the blade...attaches to the motor and it is held in place by a system of holes on a plate. Should be very cheap and very "adaptable" for your purpose. Attached find very "crude" drawing. Good Luck!!
  17. motoredrider

    motoredrider New Member


    Hello from Washington State;
    I was a motored rider for awhile, until i went to a local discount store, where i chained my bike to a lite post, only to find it gone when i came out about 30 minutes later.

    It was an 80 cc motor mounted on a mountain bike, it really was nice for about 2 weeks:(
  18. seabillco

    seabillco Member

    motor pivot

    FWIW, I just built a friction drive, rack mount for my mountain bike.
    I bolted the engine to a piece of 1/2" plywood and then bolted the plywood to a strap of steel used to hold a 4x4 post for fencing.
    The steel had a threaded hole and a long, lag bolt. I found that the bolt fit nicely in 1/2" aluminum tube. I brazed the tube to an aluminum strap which I then bolted to my frame.
    At that point, the bolt goes through the tube and the engine pivots around the bolt. I just put a handle on the other end and you can pivot the engine on and off the tire as needed.
    I hope this helps.
    Here's pictures.

    Steve G
    Grants Pass, Oregon

    Attached Files:

  19. brendonv

    brendonv Member

    Whipper snippers older than about 8 years dont have clutches, new ones have centrifugal clutchs. I have one 30cc without and one 31cc with.