Problem with woodruff key HELP!!!!

Discussion in '2-Stroke Engines' started by tomahawk, Dec 1, 2010.

  1. tomahawk

    tomahawk New Member

    Skyhawk 66 woodruff key will not stay in place. Ground 3 keys up and still no luck. If anyone has the facility to make me a collar that would bridge the gap between the small sprocket and lock over the woodruff key to keep it in place would you please please help me out. The key seems to be popping out the backside of the sprocket and getting ground up behind the big sprocket.
     

  2. AussieSteve

    AussieSteve Active Member

    I just noticed that you've had no replies, so I'll get the ball rolling.....
    Which woodruff key are you talking about? (There are 4 - one on the primary gear on the RHS end of the crankshaft, one on the clutch base, one on the magneto rotor and one on the countershaft sprocket.)
    It shouldn't be possible for any of them to slip out due to their crescent shape.

    I can't picture what you mean by a collar to bridge the gap

    A little more info, please, tomahawk and by the way, welcome to MBc.
     
  3. tomahawk

    tomahawk New Member

    The small gear that meshes with the larger gear for the clutch. And you are right it shouldnt be possible for any woodruff key to pop out, however this is the problem and i dont know of any other way of dealing with it than having a collar that spans over this woodruff key and locking it into place on the shaft.
     
  4. GearNut

    GearNut Active Member

    How far will the gear go on with the woodruff key removed?
    I am trying to determine if you are dealing with a taper issue between the shaft and gear or perhaps a keyway issue between the shaft and gear.
    I have had gears that will not seat fully on the shaft due to mismatched tapers. The only remedy is to swap out the gear with another one that has a slightly larger taper.
    I have also dealt with a key notch on the shaft that was not cut deep enough to allow the key to seat. Same with the key way in the gear. That is easier to remedy. just file the flat side of the key to shorten it's overall height.
     
  5. AussieSteve

    AussieSteve Active Member

    tomahawk, are you saying that the woodruff key is still visible when the gear is in place?
    It should be completely inside the gear.
    A pic would help.
     
  6. tomahawk

    tomahawk New Member

    hmmm havent tried putting the gear on without the gear i will try today. The bevel gear and woodruff key are flush with the shaft. I cant take a picture right now cause ive ordered a new bevel gear. Old one got chewed up. How far should that bevel gear go on to the shaft?
     
  7. AussieSteve

    AussieSteve Active Member

    When the woodruff key is in place and everything is aligned properly, the gear should still go on as far as it does when there is no woodruff key there. The woodruff key is only there to stop the gear slipping on the shaft. I'd say that's your problem. ie. The gear hasn't been sliding fully over the woodruff key.
    Good luck when the new gear arrives. Did you also buy a couple of spare woodruff keys? It can be hard to find that exact size elsewhere.
    Keep us informed.
     
  8. tomahawk

    tomahawk New Member

    Well that shines a new light on the subject. Yeh i ordered couple extra woodruff keys too. I get my new gear next friday and i sure want to be rid of the problem.
     
  9. AussieSteve

    AussieSteve Active Member

    Good one - we might have hit on the problem. As I said, keep us informed of how you go when the new bits arrive.
     
  10. tomahawk

    tomahawk New Member

    Lets see if it works this time!!!

    I noticed when i put the screw in that as i tightened it it actually felt like i was drawing that screw on over the woodruff key unlike all the other times i have tried it. Here are 2 pictures and i know they are not good ones but maybe you can comment on them. I just hope i am on the right track here. Thanks for lookin.
     

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  11. AussieSteve

    AussieSteve Active Member

    It looks like it's on properly. Make sure you get the screw nice and tight. An impact driver is good for this. (The type you hit with a hammer.)
     
  12. GearNut

    GearNut Active Member

    It looks good to me too. One word of caution though, be absolutely sure that none of that dried up red loc-tite gets in between the shaft and gear. If it were to do so, the taper of the gear and the taper of the shaft will never be able to seat together properly. This will cause the gear to run wobbly, accelerating wear between the two gears and also quite possibly lead to the mounting screw coming loose in the future.
    Upon final assembly, very light film of oil is the only thing I would allow to get between the two parts, and this is only because of the poor quality control that these Chinese parts get manufactured to. I cannot trust that the poorly finished tapers can actually mate to each other without a little slipperyness involved. Taper locked parts actually should always be assembled absolutely dry. No oil, grease, ect.
     
  13. tomahawk

    tomahawk New Member

    Thank you for your help i really do appreciate it. I will let you know of any updates.
     
  14. ibdennyak

    ibdennyak Guest

    OK, been a long time since I worked on a happy time, but from your second picture, is it possible you are installing your gear backwards? ie. with the small side of the taper in? I don't remember what the other side of the gear looks like, but ummm, I did that once. Took me half a day to figure it out. Actually, my gf's son at the time figured it out......he was 12....:goofy:
     
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