my 49cc modification/build thread

Discussion in 'Motorized Bicycle General Discussion' started by needtransportation, Mar 23, 2014.

  1. needtransportation

    needtransportation New Member

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    Last night I tore my engine down and port matched the intake and exhaust and cleaned up the ports, the hole in the intake gasket was probably half the size of the actual port. The base gasket covered probably 1/3 of the transfer port and there was a nasty casting lip where they enter the cylinder that I had to remove. I also sanded down the head mating surface til about half the raised lip was gone and I halfass sidegapped the plug and ground the the strap to a point. I just took her for a test drive and I noticed an increase in power across the board but particuly in the lowend and she also revs much more quickly but I think ill need to tune the carb a little and possibly jet up a size or two. I wouldnt say she runs like a raped ape yet but the gorilla has definitely been touched in an inappropriate way. Thank you to bikenut for your thread on how to reinstall the cylinder, I was having a **** of a time putting the piston in the cylinder u til I saw on there that there are pins in the ring lands that I had to align to.


    Things to come: larger sproket, I had planned to go to a 56 from my 44 but someone recommend that I go with a 48 and that would provide a noticeable increase In pulling power withojt sacradicing too much speed but im only shooting for 25mph and the ability to climb all the hills around me.

    The pipe I currently have is approximately 12-16 inches of header then a small expansion chamber then more small pipe followed by a coke can sized muffler, I had planned to buy an x chamber but from what ive read the setup I have is ideal for lowend torque but im not sure what im going to do.

    I found some v brakes including the movable portion that pinches the wheel, the cablea, and he levers for 25$ so ill do that out if my nexr check for sure.

    Im looking for a generaror and headlighr but all the ones I find online say they wont live at speeds above 15-20. Suggestions and advice will be appreciated.
     
  2. Theon

    Theon New Member

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    Check your plug colour, and try adjusting the needle first.
    often need to slightly down jet, to get them to run better, but a little rich is better for hill climbing.
    48t sprocket will probably be better than 56, unless you want to climb mountains.
    And get a battery powered LED head light, generator headlights suck.
     
  3. needtransportation

    needtransportation New Member

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    Im very forgetful and would never remember to keep my batteries fresh and I have to be at work at 4am so a headlight is a must. I figure ill wire up a 6v powerwheel battery to the generator and hook the light to it so that I build a charge at higher speeds and still have light when im stopped
     
  4. Greg58

    Greg58 Well-Known Member

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    A L.E.D. headlight is the way to go, much better light and uses less power.
     
  5. mapbike

    mapbike Active Member

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    LED light is way to go as has already been mentioned..... and yes the 48T is the better choice for sprocket size

    Charge the battery same time you plug in the cell phone or set the alarm clock, prioritize it with something else and that helps to remember.... for me it does anyway.....lol

    Map
     
  6. needtransportation

    needtransportation New Member

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    http://m.ebay.com/itm?itemId=310893210738 just ordered these and will report back on my results.

    Is this a good headlight? I saw that it originally sold for 80 and the reviews are positive when a diffuser lens is added.
     
  7. mapbike

    mapbike Active Member

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    xct2
    The link you posted here goes to the caliper brakes....
     
  8. needtransportation

    needtransportation New Member

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  9. mapbike

    mapbike Active Member

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    Yes that is a good bike light, I have one that I bought a couple years ago when they cost about three times what they do now and it still works great, it is a very very bright LED light, you can find extra battery packs for them also.

    You'll enjoy it but I will warn you that if you mount it close to a wireless digital speedometer it will interfere with the speedo and make it go crazy until the light is turned off.

    Map
    .wee.
     
  10. needtransportation

    needtransportation New Member

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    Ithanks for the input map Ill be picking that up soon, it was just hard to beleive quality could be had at that price
     
  11. mapbike

    mapbike Active Member

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    I ordered mine off ebay right from mainland china, but it looks just like the light in the link you listed, mine was rated at 1800 LM ( lumens ) but im not so sure those lights aren't all the same, I've used mine for a headlamp for varmit hunting and as a head light on my motorized bikes, battery life is good especially on low beam, mine came with a 6400mah battery pack and will last about 30min on high beam fully charged, they make a 10, 000mah battery pack for them that should increase life to at least 45+min on high beam, I plan to buy a couple of those in the future so Ill have a couple hours of headlight on bright time, I live several miles from the nearest town out in the sticks so its very dark out here at night and I have to be cautious of deer, wild hog and all the usual vermin running around out here at night so I run my light on brightnout here on the back roads but if I ride into town all I need is to run it on low beam, it is still realy bright and the street lights give plenty of light to see so the headlight is just mainly so others can see me coming down the street.

    Map
     
  12. needtransportation

    needtransportation New Member

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    The brakes came today but they wont work on the back because they are a little short and grip the tire instead of the rim even when I adjust the angle of the pads.
     
  13. mapbike

    mapbike Active Member

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    must be calipers for 20'' wheels instead of 24-26''..... the ones for 20'' wheels are shorter.

    almost made that mistake myself one time, cant remember the measurements for each but I have seen some ebay vendors put it in there description so you know for sure which ones they are.

    map
     
  14. mapbike

    mapbike Active Member

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    http://www.ebay.com/itm/NOS-PAIR-BL...231093826541?pt=US_Brakes&hash=item35ce43f3ed

    this fella shows the length of the calipers in his discription, the brakes you need for a 26'' wheel bike is calipers with 4'' arms and I bet the ones you have are either 3 1/4'' or 3 1/2'' arms, he has several calipers with the right length arms for the 26'' bikes.

    its been a while but I have bought from this guy before and he is a good seller

    map
     
  15. Greg58

    Greg58 Well-Known Member

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    #15 Greg58, Mar 30, 2014
    Last edited: Mar 30, 2014
  16. needtransportation

    needtransportation New Member

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    Sorry I didnt post back but Ive been busy and pissed. I ended up mounting the caliper under that small crossbar instead of on top and it lined it up perfectly, unfortunatly on her first safe ride I threw the engine drive chain and it caught between the sproket and wheel and bent my wheel pretty badly. I was having trouble keeping to rear wheel centered between the rear triangular bars and the front of the wheel kept wanting to move left so I know what caused it I just dont know why it wouldnt stay centered and straight. I will either be getting a new wheel from a local guy from craigslist tommorow depending what he has in his spare parts or ill order one in a few days and try to figure out what was causing the issue.
     

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