skyhawk 66cc clutch trouble

Discussion in 'Frame Mounted Engines' started by Arlonious, Jun 13, 2010.

  1. Arlonious

    Arlonious New Member

    im installing a skyhawk 66cc engine on my schwinn jaguar beach cruiser but i think something is wrong with the clutch no mater how far i push the lever to disengage the drive shaft it wont disengage so i opened up the right side of the engine exposing the clutch plate and when i pull the lever it only pushes out one side of the clutch plate also the flower nut on the other side doesn't have a groove going along it to adjust it which is described in the manual i am kind of a beginner with these engines i heard the plate could be sticking from sitting for a long time and that if i hit it with a rubber or raw hide head hammer it could un-stick it if any one can help or clear up for me why the clutch isnt working it would be greatly appreciated thank you
     

  2. GearNut

    GearNut Active Member

    The item that is struck is the shaft (called a bucking bar), about the diameter as a wooden pencil, that sticks out of the center of the sprocket shaft on the left side of the engine.
    You have to remove the sprocket cover/ clutch release to get to it.
    The bucking bar is only held in place by a little bit of grease as assembled by the factory.
    Be careful that it does not fall out when the cover is removed.Behind the bucking bar is a single ball bearing, the same diameter as the bucking bar. It may fall out too.
    After the cover is removed and all the other parts are in place, use a piece of hardwood or plastic to protect the end of the bucking bar, strike the bucking bar firmly with a hammer to jar loose the clutch internals. Do not hit is so hard as to knock it into next week, you do not want to damage anything.
    While you are in there it is a good idea to remove the bucking bar and single ball bearing and put a glob of quality grease inside the hollow shaft. Replace the single ball bearing followed by the bucking bar. Wipe clean any excess grease that may have squished out, but leave a little on the tip of the bucking bar to help lubricate the clutch release cam (in the cover you had to remove) to bucking bar contact area.
     
  3. GearNut

    GearNut Active Member

    As for adjusting the flower nut, (you obviously have the clutch cover off all ready) first remove the small lock screw that fits into one of the notches in the flower nut.
    Now squeeze in the clutch lever and use some tape or a piece of wire to hold it in all the way against the handlebar grip. Now all the clutch spring pressure has been relieved from the flower nut and it should be easy to turn with your finger tips.
    Turn the flower nut all the way in until it is snug tight. Turn it back out about 1/2 to 1 turn and align one of the notches in it with the screw hole for the lock screw. Start the lock screw back into the pressure plate, don't tighten it yet, just run it down snug.
    Now remove the tape or wire holding the clutch lever in tight to the handle bar grip.
    Let the clutch engage. This will hold the pressure plate for you when you tighten the lock screw. Tighten the lock screw. Reinstall the clutch cover and all should be good.
     
    Last edited: Jun 13, 2010
  4. Cavi Mike

    Cavi Mike Member

    Mine came that way also. I removed the pressure plate altogether and it made no difference, the whole unit is just very tight. I spent some time turning it and it has started to free itself up, I'm sure it will be fine once it's broken in.
     
  5. AussieSteve

    AussieSteve Active Member

    More often than not, with a new engine, this problem is actually caused by the clutch pads sticking to the plates, due to sitting for a long time after assembly.

    Best cure is to remove the RHS side-cover and jam a piece of folded rag in the top of the crankshaft cog/clutch cog to lock the engine, then pull the clutch in and pin it and roll the bike forward with some weight on it. (A bit of backwards/forwards might be needed to jolt it free.)

    If that doesn't work, remove the clover nut and outer clutch plate, then do the same, because the rear of the clutch pads could be sticking.
     
    Last edited: Jun 14, 2010
  6. Arlonious

    Arlonious New Member

    thanks ill give all that a try in a couple of hours and let you know if anything worked i still have a few ideas of my own as well
     
  7. GearNut

    GearNut Active Member

    Another issue that these clutches have is the little friction pads are commonly cut out just a little bit too big to fit in the "pockets" of the ring gear.
    They do not need to fit sloppy, just loose enough to wiggle a little bit so they can fully float and release when needed to.
    It is not hard to dress and deburr the edges of the friction pads with some 150 or 200 grit sand paper.
    It just takes time as there are alot of them.
    I recommend wearing a dust mask if you do this. Some folks believe that they may contain asbestos, although I do not believe that.
     
  8. Arlonious

    Arlonious New Member

    just got the clutch to disengage but when i try pedaling with the engine engaged its almost impossible to pedal should i be worried or do the pistons just need to loosen up a bit or get sort of worn in
     
  9. Cavi Mike

    Cavi Mike Member

    You're not supposed to pedal with the clutch engaged, that's what the pin on the lever is for. As for riding this bike normally, forget about it, there's way too much drag in this setup.
     
  10. AussieSteve

    AussieSteve Active Member

    Pedal up to speed then drop the clutch to bump-start.
     
  11. GearNut

    GearNut Active Member

    And keep pedaling while the engine is spinning until it finally starts. It may take 10 or 20 feet initially. You will feel some resistance to pedaling until the engine sputters to life.
     
  12. Lazieboy

    Lazieboy Member

    Grubee 66cc

    Is that a newer one ? slant plug. Ihave 1st. gereration grubee 66cc and i didnt have that issue, but it took 4ever to start 1st time. Now pops off 1st try all day. I give it a very good work out and it handles it.
     
  13. Arlonious

    Arlonious New Member

    just got the bike running and it runs great thanks for all the help it still needs a little fine tuning but it goes alright
     
  14. AussieSteve

    AussieSteve Active Member

    Good one - have fun.
    Give it a few runs to settle before looking at tuning.
     
  15. Jumpa

    Jumpa New Member

    A frugal member on here gave me an awesome tip when your clutch lever hold mechanism breaks "and it will" use 2 or 3" piece of rubber from an old bicycle tire tube works great and mine provides that extra grip when riding ,

    Also I put a spare 3"chunk on my throttle grip "Ya never know when you might need more and this provides a little give when I get over zealous on the plastic throttle and it will spin or roll on the throttle instead of breaking the white plastic throttle tube if I twist to hard when trying to beat my Buddie on his bike No fair he is only 5'5" & weighs 140 lbs soaking wet & I'm almost 300 lbs @ 6'5"
     
  16. Jumpa

    Jumpa New Member

    I have question My bike will start however the clutch has been slipping quite a bit lately. My question what else can slip besides the obvious clutch pads is there or are 5there any other parts that can slip I'm looking at a SCHEMATIC AND CANT SEE Anything THAt might be slipping. Is it just the pads that can slip? Is that the only friction point that I need to be concerned with. For some reason it just feels like it could be coming from some place else. It's slipping so bad I cant even go any more yet it will start? Pardon the pun but " What gives" :)
     
  17. Al.Fisherman

    Al.Fisherman Active Member


    Here is the picture I told you I'd send.
    [​IMG]

    From the PM I sent.....
    The clutch pad holder is bolted on the (hollow) clutch shaft (goes through the case). There is a woodruff key that keeps the clutch pad holder in place..you may of stripped the key. There is a smaller shaft that the bucking bar moves so when the clutch is disengaged the flywheel separates from the clutch pads. The small gear also has a key, of course it may also be the one stripped. And you have a key on the chain sprocket. In the meantime, I'll see if I can drag up a photo.
    Ron

    Personally...unless you have a pull start, I can't figure out how you can start the engine and it will not pull. If you have a broken key, it shouldn't start.
     
    Last edited: Dec 19, 2011
  18. GearNut

    GearNut Active Member

    Sometimes when a woodruff key shears it can result in the affected parts acting like a one way clutch. The bits of remaining woodruff key can get cocked in the shaft grooves and bite into the shaft/ gear one way but loose all their now failing bite when the load is transferred the other way.
    Sometimes this can make for a really good head scratcher!
     
  19. Al.Fisherman

    Al.Fisherman Active Member

    Just to make everyone aware, the problem wasn't in the clutch itself. The bucking bar wore away at the ball bearing end. This can be fixed permanently by using the shank of a 5/16" drill bit ground to length.
     
  20. Jumpa

    Jumpa New Member

    Thank you sir and a man of your word... I like that in a person Turns out it was the bucking bar it was mushroomed and about an eigth of an inch shorter than the extra one i had "OH YEA Thank you for the drill bit option thats geeat priceless information guess whats getting tossed into my emegancy grab bag. Or possibles bag if you will. because as any MB owner will tell ya "ANY THINGS POSSIBLE" when you ride a MB thanks again AL.Fisherman
     
    Last edited: Dec 20, 2011
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