Bike Fell over

Discussion in 'Motorized Bicycle General Discussion' started by cloud, May 30, 2011.

  1. cloud

    cloud New Member

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    Well I was at brothers house my Bike was standing with kickstand and the wind caught it and it went over and hit the ground.

    The motor is now vibrating bad when riving it up and when riding it.
    it still starts good and idles good but it does vibrate more when idling also.

    I thk it could be maybe the part of the engine that the piston is housed in, maybe it moved off center a bit and the piston is hitting it or something.

    Im not sure really what it is, I have still yet to take it apart, does anyone have any suggestions or have had this same prob let me know.

    God Bless
     
  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

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    What kind of motor?
    Presuming a Chinese 2 stroke check your motor mounting bolts to
    see if they are loose or bent.
    Are you hard mounted or using rubber?

    Is the exhaust moving around? Do you have a strap supporting the exhaust?

    Put your foot on it when it's idling to see if the vibrations go away.
    I do the same when I am riding on a street with no traffic, be careful...

    I doubt your piston theory. Any visible damage? What hit the ground?
    Start the motor with all the covers off to see if something moved??

    God Bless you too.
     
    #2 MotorBicycleRacing, May 30, 2011
    Last edited: May 30, 2011
  3. spad4me

    spad4me New Member

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    Bicycles fall down all the time.
    Without a motor so what.
    Something got loose.
    Jerk the motor back and forth.
    Did the frame crack.
    My motor mounts would always fail on a china girl.
    Until .
    They got redrilled and tapped for 5/16 american studs .
     
  4. cloud

    cloud New Member

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    Ok I thk I located the prob or at least im pretty sure I did

    I got down on the ground and noticed one of the front motor mount bolts that attaches to the U clamp for the bigger frame missing, took the muffler off.
    I stuck an awl up there to see if the bolt had just come loose and fell out but it broke off most likly due to the fall.

    Now I need to try and extract it out cause its flush with the mount nothin to grab to.

    Figures LOL

    God Bless
     
  5. spad4me

    spad4me New Member

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    Remove the motor.
    Using a dremel with a cut off wheel , or a very thin cut off wheel on a 4/12 powered tool , or a hack saw.

    Slot the center of the flush stud or bolt not worrying too much about the soft aluminium engine block.
    You must slot deep enough to reach enough of the broken stud or bolt, About 1/8 to 1/4 inch.
    Use a screwdriver slightly smaller than the diameter of the stud or bolt to unscrew the broken piece.
    To Replace the broken stud or bolt , take the other good one to a hardware store and buy an exact replacement. Or replace all the engine mounting studs or bolts with higher quality American stuff.
     
    #5 spad4me, May 31, 2011
    Last edited: May 31, 2011
  6. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    Drill a small hole in the center of the broken stud, & remove it with a small 'easy out'. ;)
     
  7. steampunk

    steampunk New Member

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    venice has the better idea...the slotted technique is usually the last ditch effort or dirty way...not meaning any offense spad4me .... the ez out is the preferred method...your auto parts store should have them...1/8-1/4 stud size...if their is a better version of the ez out available...always get it..trust me its worth it
     
  8. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

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    Grind the end of the stud flat if it is jagged with a Dremel
    so that you can...
    Center punch the stud end so your drill bit will not wander.

    Drill with a small bit making sure that you are lined up all
    the way through

    Then drill with a larger bit, reverse the drill bit before it is
    all the way through and if you are lucky the stud will back out.

    There are left hand drill bits made for this but who has one? right?

    Buy the square style EZ out. The spiral ones are junk especially
    on the small sizes. I had a great German made set of square EZ outs.

    Lightly tap the square EZ out into the hole so that it bites.

    Turn carefully as EZ outs snap easily and pray to the MB gods
    as you only got one shot to get that damn stud out!
     
  9. cloud

    cloud New Member

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    heres a pic of it

    [​IMG]

    Ya I was thking the same thing, about using an extraction bit

    thks for all the insight ppl

    God Bless
     
    #9 cloud, May 31, 2011
    Last edited: May 31, 2011
  10. steampunk

    steampunk New Member

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    you lucked out...its a clean break...ez out ...x2 on the square ones..a little more expensive but soooooo worth it
     
  11. cloud

    cloud New Member

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    what ya mean ? haha ya crazy question

    whats the x2 on the square?
     
  12. steampunk

    steampunk New Member

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    bimopd mentioned the square type ez outs...they are much better your luck its a clean break meaning you dont have to grid the top of the bolt flush...its alot more polite to the threads...its not the end of the world...ive broken about 6 of these so far for varieing reasons..just make sure to use grade 8 or above for the replacement bolts and you will be fine
     
  13. cloud

    cloud New Member

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    ok I see, went to autozone earlyer ans all they had was the circler reverse thread ez out, so I might as well try that seems to me that it wont be that hard to get out.

    I do thk im going to grind out the back mount to make a little wider opening so it will sit more flush and that way I can put some rubber there ans on the front one to cut down on the vibration.

    the hardware store sells it in 6" squares, it should help out some.

    Do you guys thk opening up the mount will compromise it?
     
  14. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

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    Before you buy the EZ out I would drill it and the reversed drill trick
    works quite often.

    Do not use rubber under your mounts as it will not help with the
    vibration and will lead to more broken studs. may make the vibes
    worse too.

    Just make your mounts flush against the bike tubes with NO gaps.
    This is the tested and true method by those who have any experience.
    Yes.
    Fatal last words.
    If you break an EZ out off and can't get it out you are screwed.
    They are hardened steel and almost impossible to drill out.

    x2 means times two
     
    #14 MotorBicycleRacing, May 31, 2011
    Last edited: May 31, 2011
  15. cloud

    cloud New Member

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    hey, I got it out pretty easy. I tried the drill bit method lol, and it worked. I used a 7/64 about 1/8 deep then got a size bigger, and it came right out real easy in reverse.
    Oh and I ground the mount out a little and now sits flush, haha it might help remove some of the normal vib.
    I got about a half a tank left of the 24:1 then going to start using 32:1.



    Thks guys
     
  16. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

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    That's great news about the broken stud.

    Forget about 32:1 oil mix. The hot tip for these motors is Opti-2 oil
    at 100:1 from mile one.
     
  17. cloud

    cloud New Member

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    Hmm Ive never heard of anyone running 100:1, seems like it wouldnt be enough oil

    The highest ratio I would go is maybe 40:1, but I wouldnt be agianst experimenting with higher just to see how it does.
     

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