​Woodruff key

Discussion in 'General Questions' started by calebbullock, Nov 8, 2013.

  1. calebbullock

    calebbullock New Member

    So i've been riding my 66/80cc flying horse (black) bike engine for a few months now. I have ran into some problems that have happened a few times in the past month. Mostly it has been the Woodruff key. It has sheared off 3 times now am im starting to get annoyed. I have gone to a store that has a key that i think is too small and is on the english system scale (size 3/16). If i am correct i am supposed to use a 3mm (metric system) key on the end of the drive shaft. I am still learning all the little nooks to my bike and am looking for some good hard facts concerning the Woodruff key on my bike.



  2. crassius

    crassius Well-Known Member

    there are many diff sizes/shapes of keys on these bikes depending on which factory or which year they came from - one thing that seems to remain the same is that both keys on the same shaft will be the same size/shape, so take out the key on the other end of the shaft & use that as a guide
    mosquito13 and calebbullock like this.
  3. Fabian

    Fabian Well-Known Member

    The woodruff key is not designed to be the primary method of transmitting engine torque to the small crankshaft gear. The press fit is what does all the work, which is why you need to install a gear puller to remove the small gear.
    I am suspecting that you haven't used the hammer and punch method to tighten the large faced screw into the end of the crankshaft, and onto the small gear; driving it home to form a good press fit.
    calebbullock likes this.
  4. darwin

    darwin Well-Known Member

    HF carries a woodruff[?] key kit that costs a few bucks. You'll have 10 sizes you'll never use but at least you'll have 3 or 4 of the right ones.
    calebbullock likes this.
  5. calebbullock

    calebbullock New Member

    Thanks. just gotta run over and get the key
  6. darwin

    darwin Well-Known Member

    Ace hardware has those also.
  7. Josh Ramich

    Josh Ramich Guest

    Hate being stuck with it, f**k China