Engine won't turn over

Discussion in 'Motorized Bicycle General Discussion' started by pop-leon, Apr 23, 2011.

  1. pop-leon

    pop-leon New Member

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    I have a new 60cc sky hawk bike engine.Every thing is lined up good and my bike peddles easy with clutch in free wheeling position. MY problem is that when I release the clutch to start the engine it won't turn over and you can't peddle it. The engine turn's over fairly easy with the plug out. (HELP)
     
  2. Al.Fisherman

    Al.Fisherman New Member

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    What I would do is remove the chain, remove the magneto cover and use a ratchet and a socket and turn the engine over and see it it locks up. If it does, change to a NGK plug (might be a different in the reach) you need to do this and a new plug lead anyway. If that fails, remove the head, and try to rotate the crankshaft. If it doesn't lock up, add a extra head gasket, maybe 2. While you have the head off...mill both head and cylinder, using some where around 250 grit paper on a flat service (glass). Only remove enough that you can see that the surfaces are flat. I have never seen a head that wasn't warped.
     
    #2 Al.Fisherman, Apr 23, 2011
    Last edited: Apr 23, 2011
  3. pop-leon

    pop-leon New Member

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    Thanks for your info Ron.This thing is really baffling me. I have installed 6 others with no problems. I can turn the engine over by hand with the wheel but when I try to start it by peddling at a good speed it will turn over once maybe twice and that is it before you can't peddle any more.

    Leon. N.C.zpt
     
  4. pop-leon

    pop-leon New Member

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    Ron as you suggested I removed the magneto cover. The engine worked like a charm.:-||
     
  5. Al.Fisherman

    Al.Fisherman New Member

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    So what you are saying is that the engine turns over easily without the magneto cover but won't turn over with the cover installed...???
     
  6. wayne z

    wayne z New Member

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    What he's saying is that it wont turn over when he releases the clutch. Sounds like the clutch is not grabbing hard enough. Could be oily plates ect or not enough slack in cable or the heavy internal spring not tight enough.
     
  7. Al.Fisherman

    Al.Fisherman New Member

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    1. Remove the spark plug

    2. Remove both the magneto and clutch cover (both are on the same side)

    3. Take a socket and rotate the magneto shaft. The 11 tooth gear should rotate.

    4. Replace the 11 tooth cover and rotate the magneto shaft with the clutch disengaged. I just did this to a engine in my vise and I can hold the clutch arm with my finger. If you can't, use a BOX wrench as leverage.
    With the clutch disengaged (pressure on arm), turning the magneto shaft, the 11 tooth should remain still.

    5. Repeat these steps again with the spark plug installed.
     
    #7 Al.Fisherman, Apr 24, 2011
    Last edited: Apr 24, 2011
  8. pop-leon

    pop-leon New Member

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    Wayne It peddles real easy with the clutch lever in but when the lever is released it is like the engine freezes up almost like too much compression. I can pick up the back wheel and turn it with my hand and the engine turns over. It is not as easy as some of my other engines I have installed.

    Ron. I tried what you said. Every thing works as it should.

    Leon. Hatteras,N.C.:-||
     
  9. dmb

    dmb Active Member

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    how much compression? i'd unplug the cdi pull the plug spray wd40 in the hole then try riding it. if it still locks up could be the piston hitting the head [should be able to hear it] or tight bearings [more oil & riding, last or first check chain / case /alinement / clearance some times they rub the cover [mine did] good luck dennis
     
  10. dmb

    dmb Active Member

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    sorry, always check compression with the throttle wide open, gotta git air
     
  11. mapbike

    mapbike Active Member

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    How fast are you moving when you release the clutch?

    If you are just barely moving it will seem like a tight new engine is locking up when you release the clutch lever sometimes, you need to get up to a good speed and then turn that lever lose as your pushing down hard on the peddle and keep peddling, if the clutch isn't slipping that engine will spin over, but if you are just barely moving when you release that clutch you aren't likely to spin that new engine over if it's a good tight one like one of mine was.

    I haven't read all the post here so I may just be echoing someone else and if I am I appoligize....

    Peace






     

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