What typically fails on a ChinaGirl motorized bike

Discussion in 'Motorized Bicycle General Discussion' started by Deimus, Dec 14, 2012.

  1. 2stroker

    2stroker New Member

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    you just described my kit. very good functionality running smoothly sipping fuel. add simple and reliable and it sounds like my 26cc friction kit..
     
  2. Deimus

    Deimus New Member

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    You left out "form" though. :) Just kidding you. Of course, I realize that beauty is in the eye of the beholder. For me, the engine fits in the frame and not on the wheel. And I like seeing a lot of daylight around a slim engine.

    You know, I omitted the most important first criteria. "Fun". That is actually the most important thing. We should love spending time with our bikes be it riding or tinkering or hopefully both. I enjoy seeing the build threads of anyone's bike because it allows me to share in what they are wanting to build. And after it is finished, I can appreciate the machine they built even if it wouldn't be the type I would want to build myself. I'm new here so I hope my posts come across this way.
     
  3. 2stroker

    2stroker New Member

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    It should def. be fun! If your not enjoying yourself you might wanna see a doctor. Ya like the fact my kit never breaks on me. Thats why i ride the kit that i ride. Some people are in it for looks and speed. Im in it for reliability and fun! It sucks being 20miles from home and pedaling because your kit broke down. Its never happened to me but im sure it wouldn't be any fun. what kit are ya building?
     
  4. MotoMagz

    MotoMagz Active Member

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    I think a 2 stroke is a great starting point. If you are able to put some cash into them they can be very reliable and fast.Some members are like magicians with these lil engines....But not me. Once I rode my first 4 stroke I was sold and will never go back.Good luck!
     
  5. Deimus

    Deimus New Member

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    Kulana MoonDog with Flying Horse 66cc kit

    The link above is to my first motorized bike project. I've only finished it for a week now and the weather has only permitted a little of the break-in riding so far. :)
     
  6. the chief

    the chief New Member

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    on the fender mounts breaking, lots of people go to walmart and buy a throw away bike, then wonder why stuff breaks, the difference in the strength of brackets between a decent fender set and the ones that come on those is very nociticable having worked on both.
    the main problem with these kits is that they make installation sound far easier than it actually is, if you don't know what you are doing you will most likely have problems when setting up. my first bike the loose ball bearing (behind the bucking bar) fell out without me being aware of it, 14 hours wasted trying to figure out why my clutch would not disengage. this wasn't the kits fault it was mine. third build i over tightened the motor mounts, they snapped, not the kits fault, it was mine. when installed correctly they are pretty reliable, its all upon the installer, remember, we are turning bicycles in to motorcycles, it does require some skill and knowlegde.

    here is my two cents, if you plan on buying the cheapest bike from walmart then plan on ditching alot of parts, especially the wheels.
    if you upgrade the wheels you can use the stock rag joint, but a hub adapter is still the way to go, a stock rag joint will destroy the spokes on a cheap wheel, some people have gotten away with this, some people have also gone over niagra falls in a barrel and lived, that doesn't mean you should.
    use half links to avoid the chain tensioner, if you do use the chain tensioner pack it with quicksteel to keep it in place, if you design a piece like this to fit every bike, it won't fit any bike well. the problem is the extra space between the frame and tensioner allows rotation, fill this with quicksteel and you wont have problems.
    be careful not to overtighten the motor mounts, and remember chains stretch and the mounts tend to settle a bit, upon completion take ONE ride around the block and go back over the motor mounts and chain tension. checking EVERY time you ride it for a bit, the mounts usually only take one adjustment the chain will stretch for awhile. if you notice things are loose you can always go back and retighten them, on the other hand if you overtighten and bow the studs out, they are now weakened and you cant go back.
    the sparkplug caps are cheap, real cheap, probably the only thing i really take issue with, use them until they break then replace with ngk cap, note, don't remove cap from plug unless you have to and they will last longer.
    listen to your bike! very seldom do the bikes just break, they usually give warning first, a sound a vibration etc, listen to it, it will usually give you a heads up.
    number one, unless you are a stubborn sob like myself, get on the forum and read. ask some questions, i enjoy the hard way, that doesn't mean you will.
     
  7. 2door

    2door Moderator
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    Well said Chief.
    If everyone followed that advice we wouldn't see so many dissing the 2 stroke engine kits. They take a little mechanical common sense to install and maintain. Just bolting one on and expecting that you'll have a Honda or BMW under you is why so many find the Chinese 2 strokes a problem.

    I've preached for years that the biggest problem with the HT (Chinese kits) is the level of mechanical skill required to properly install and maintain one. The ones who hate them the most are usually the ones lacking the skills necessary to keep them running. There are exceptions to this but those who have the skills have sometimes found the 4 strokers more to their liking for various reasons. However the majority of haters are those who don't have the skills required to install them or understand the basics of 2 stroke engines and what it takes to get the most from them.

    Tom
     
  8. GearNut

    GearNut Active Member

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    Geeze 2door!
    I couldn't agree more!
    Also, while re-reading your post, I realized that if you replaced the HT kits as the subject of your post with a computer instead, the same logic still applies.
    Shoot, it's application is universal!
     
  9. Deimus

    Deimus New Member

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    Well I was able to finish off my first tank of break-in fuel today. The little engine just keeps getting smoother. I credit much of this experience thus far to the information I've taken from this forum.

    A recent example: After reading about the half links in the tensioner thread, I went back to Tractor Supply this morning and got a package of offset links for the #41 chain that I got from them a few days ago. I'll put one of these on tomorrow so I'll be able to run without the tensioner installed. I was able to run without the tensioner with the kit supplied #415 chain but not with the new Tractor Supply #41 chain. By the way, it is amazing how much better constructed the #41 chain is compared to the loose construction of the #415 kit chain.

    While I have the #41 chain off, I'm going to clean the grease off it that it came with and lube it with a clean chain lube. That storage grease it came with is too messy to run.

    A second change I'm making now isn't from information from this forum instead it is just from general reading I've been doing on the Net. I'm glueing a piece of rubber to act as a sound dampener to the inside of my gear cover to dampen some of the gear noise/ringing I get from it. I had read that this cover is like a bell and a significant source of noise and for me that is true. I'm going to adhere it solid with spray on glue to get the maximum benefit of the dampening. I think this will give me the best results.
     
    #29 Deimus, Dec 20, 2012
    Last edited: Dec 20, 2012
  10. GearNut

    GearNut Active Member

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    That will go a long way to quieting the gear whine.
    Another trick you can do it stuffing small, snug fitting blocks of rubber in between the cylinder fins. The fins do actually ring with every power stroke similar to striking a bell.
    Quickly drag a screwdriver handle across the fins, from the cylinder head to the base gasket, to hear what I am talking about.

    I also have dampened my clutch cover, but I used cardboard and black RTV silicone.
     
  11. Deimus

    Deimus New Member

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    I did read about the rubber in the fins here. And I saw the photos showing where to place the rubber. But the idea of it blocking the air flow still has me concerned. It seems like it must affect the cooling capacity of the fins.

    I do have rubber left over from a hockey puck I cut up for the front motor mount. Perhaps I can cut "buttons" from it and stick in the fins leaving an opening between the button and the cylinder. This would not block all of the airflow. Hmmmmm....
     
    #31 Deimus, Dec 20, 2012
    Last edited: Dec 20, 2012
  12. GearNut

    GearNut Active Member

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    If you keep them small they will not interfere much with the air flow.
    Mine are about 3/8" wide and 1/4 inch deep.

    All of my modern dirt bikes came with them from the factory and none of them have issues with overheating, even when playing in the mud. High RPM and low MPH.
     
  13. Deimus

    Deimus New Member

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    Very good. I will add this to my task list for tomorrow. I will follow your dimensions as well. Thank you.
     
  14. DaveC

    DaveC Member

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    3 motors, 3 magneto fails. Which is why there's a Morini motor going in my next build...if and when I'm feeling well enough to finish it :p
     
  15. Deimus

    Deimus New Member

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    Can you be more specific about what failed in the motors? Was it different failures in all 3? Thanks.
     
  16. DaveC

    DaveC Member

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    First motor I got was BGF 66, never ran. Sent it back. The replacement ran...until that magneto failed. Ordered a 49, it also never ran. I got so disgusted I sold it all off. Can't be specific, I just wanted the crap gone :p
     
  17. Deimus

    Deimus New Member

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    Sounds like you made the right choice for you. I hope your next build works out better. So perhaps fourth time will be the charm.
     

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