Motorized Bicycle Chain Noise

Discussion in 'Instructions for Building and Repairing Motorized ' started by 2door, Mar 13, 2009.

  1. 2door

    2door Moderator
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    There has been a lot of discussion about clutch/chain noise from the 2 stroke Chinese engine. I've found one source that anyone with a Dremel tool or a grinding stone in a drill can cure. Both of my engines, one from Dax, the other a Chris Hill motor, had chain interference with the clutch actuator cover. The photos show where I found the chain was hitting inside the cover and what I did to eliminate the contact. After this modification my clutch/chain noise was dramatically reduced. It's easy. Give it a try.
    Remove the clutch actuator cover, look for the telltale marks on the inside of the cover where the chain has been hitting. (photo 1) I used a Dremel tool with a sanding drum but any abrasive tool will suffice, to remove enough material to widen the space between the cover and the chain. After grinding the relief area I installed the cover and spun the rear wheel with the clutch dis-engaged, and looked for any spots that were still hitting and then ground off just a little more material.
    The attached photos are self explanatory. Any questions, just ask.
    Oh, and before you tell me my chains are too loose...no, they're not.
    Tom
     

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    #1 2door, Mar 13, 2009
    Last edited: Apr 2, 2012
    chmn22s likes this.
  2. Large Filipino

    Large Filipino New Member

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  3. Retmachinist

    Retmachinist New Member

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    Tom, I had noticed the same marks on all of my chain covers. They all made a quick trip to the mill where that was eliminated. Good Find!

    John
     
  4. Dave31

    Dave31 Moderator
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    Excellent 2door...

    Mine did the same thing in the same spot. You can also see where it was hitting in a different spot.
    I was going to do a thread on maintenance and things to look for and all that good stuff, and this is one of the things I was going to point out.

    I have since decided not to do that thread.
     

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  5. 2door

    2door Moderator
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    Since I first posted this thread I've found the identical problem on three other engines. That makes five total, two from one supplier the other three from different ones. This tells me it is probably a common problem on most if not all Chinese 2 strokes. This is a modification that almost anyone can make in less than an hour. The reduction in chain to case noise has been very noticable on all my engines so if you'd like to quiet your bike a little give this a try. These photos are a little better than the originals...new camera.
    Tom
     

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  6. rohmell

    rohmell Active Member

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    It's good to know that this is a common problem, and not due to an EFF-up during kit installation.
     
  7. 2door

    2door Moderator
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    Just bumping this old thread because I found the same problem on 2 new engines in the last few days. Looks like the factories haven't addressed a problem that's been with us for years.
    The situation is exactly as described in this old tutorial that Paul was kind enough to dig out of the archives for me. Thanks, Paul.

    Tom
     
  8. wildwood

    wildwood New Member

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    If you don't want to modify the motor a quick redish of the rear axle might line that chain up
     

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