How to test if clutch works.

Discussion in 'Transmission / Drivetrain' started by supernova, Nov 21, 2010.

  1. supernova

    supernova New Member

    I have a new SkyHawk 48 and this it the first 2 stroke engine I've worked with. It's mounted and the chain drive is installed. I assumed that if a engaged the clutch arm the inner sprocket would be free. However, I'm not noticing any difference whether the clutch is engaged or not. I'm pushing the clutch arm in as far as it will go and no change. Back wheel refuses to coast.
     

  2. Al.Fisherman

    Al.Fisherman Active Member

    Quite common issue with these clutches. Suggest you do a search as this topic has been covered many times.
     
  3. Stan4d

    Stan4d Banned

    :stupid2:

    Not that Al is stupid, but he did say it all.
     
  4. GearNut

    GearNut Active Member

    The biggest mistake I see with new builders is they do not adjust the clutch cable tight enough. When you push the release lever inwards until it stops, you have only removed all the free play inside the release mechanism. From that point on the resistance felt is the heavy clutch spring inside the engine case getting compressed. With the hand lever on the handlebars fully out (clutch engaged) the cable should only have a slight wiggle to it. 1/8" or so freeplay.
    As stated before, this subject has been brought up again and again and again and again....ad naseum.
    A search on this site would do you wonders.
     
  5. supernova

    supernova New Member

    Thanks for the replies. As noted, I've only mounted and chained the beast. Not really sure what I should be expecting with mechanical assumptions until it's all built. I guess I'm jumping ahead of the gun.
     
  6. GearNut

    GearNut Active Member

    Patience grasshopper. Don't play with the toy until all the parts have been properly assembled. ;)
     
  7. supernova

    supernova New Member

    The bike is completely installed except for fuel. The clutch has been adjusted to all specifications found in the many CLUTH ADJUSTMENT THREADS. However, I still have not found a thread with the answer I'm looking for.

    Should the rear wheel rotate freely when clutch is engaged? I am assuming it should! NOTE: Engine has not been started and no fuel has been added until I can get this resolved.

    Any clues as to which tread covers this?
     
  8. arkives1

    arkives1 Member

    how to test if clutch works

    The rear wheel will not turn freely if the clutch is engaged. When you squeeze the hand lever you are disengaging the clutch.At that point the wheel will turn and it will still move the chain and turn the drive sprocket on the engine which is now independant of the engine until you let the lever out again. There will be some drag from that small sprocket and the chain moving but the bike will certainly coast if the clutch lever is squeezed. Assuming of course that you have adjusted cable correctly.
     
  9. supernova

    supernova New Member

    OK. Lets take the cable out of the equation. If the clutch arm is fully pushed towards the engine, and the clutch pin is fully seated as far as it will go, and the drive shaft still is engaged then there is a major clutch problem. Correct? Because this is what is happening now.
     
  10. supernova

    supernova New Member

    Or another way...

    The rear wheel will not turn freely if the clutch is engaged.
    OK. Makes sense.

    When you squeeze the hand lever you are disengaging the clutch.At that point the wheel will turn and it will still move the chain and turn the drive sprocket on the engine which is now independant of the engine until you let the lever out again.
    No. Mine does not.


    There will be some drag from that small sprocket and the chain moving but the bike will certainly coast if the clutch lever is squeezed. Assuming of course that you have adjusted cable correctly.
    I don't believe it is a cable adjustment problem at this point. I think there is something wrong in the clutch mechanism.

    This is a brand new motor. I've even looked at the clutch itself. Not sure what I should be looking for if something is amiss.
     
  11. arkives1

    arkives1 Member

    how to test if clutch works

    If you are pushing the lever fully until it stops including the resistance of the clutch spring which is quite strong, the clutch should be released. If it is not releasing the problem lies within the clutch itself. There are many threads on this forum about adjusting and repairing these clutches. Are you feeling the resistance of the spring? It's possible that the rotatating buck bar in the sprocket cover is not in the proper position. There is a flat spot that seats against the push rod that goes into the clutch through the sprocket. This rod pushes against a ball that pushes the clutch plates apart. Take the sprocket cover off and check that the clutch arm and buckbar are in the right position. The lever and that bar should rotate easily. Hopefully someone on here will have a photo that shows the right position. Hope this makes sense. If the buck bar and push rod are in correctly it's possible that the ball bearing is missing. Pull the push rod out of the sprocket and shake the ball out, if it's not there you have your answer. The other simple possibility is that the flower nut on the other side of the engine in the outside clutch plate is way too tight. Hopefully you have found clutch adjustment threads here and will know what I mean.
     
  12. supernova

    supernova New Member

    Are you feeling the resistance of the spring?
    Yep
    Take the sprocket cover off and check that the clutch arm and buckbar are in the right position. The lever and that bar should rotate easily.
    Taken it off about 15 times today trying to diagnose the problem and they are in the right positions.

    If the buck bar and push rod are in correctly it's possible that the ball bearing is missing. Pull the push rod out of the sprocket and shake the ball out, if it's not there you have your answer.
    Interesting. The ball should just fall out huh? Hmmm......
     
  13. supernova

    supernova New Member

    I was hoping not to see a bearing, but there IS a bering in there. But it won't just fall out. I think it's suctioned in grease. Photo Attached
     

    Attached Files:

  14. Jeco

    Jeco Member

    I think you need to adjust the flower nut on this.
     
  15. supernova

    supernova New Member

    Thanks for the reply. I found my answer. I had to do a bearing break operation. Found the answer on the motorbicycles.com site. Evidently the clutch grease needed to be broken loose. They had a very nice photo manual on how to accomplish this. Have a great T Day.
     
    Last edited by a moderator: Nov 25, 2010
  16. Stan4d

    Stan4d Banned

    Are you searching this site at all?
     
Loading...