gt2-a 7g 4- stroke build

Discussion in 'Photos & Bicycle Builds' started by aceinthesky, Feb 3, 2015.

  1. aceinthesky

    aceinthesky New Member

    First off, I want to thank migueralliart, and kcvale for helping me with this build.

    Well after two months I finally have my build 95 percent complete. Took for a few miles around town and it feels like a small motorcycle, the shift kit is awesome. I, also did a few bolt-ons to the huaseng motor for more power.

    one think, I realize about this build and to anyone who wants to build a 4 stroke bike with a skyhawk frame, is not to use the gt2a-s frame, even though its designed for 4-stroke. Use the gt2-a frame which is meant for a 2 stroke build and cut off the front mount. There is not much room in the gt2a-s frame for a 4-stroke.

    gt2-a frame:
    power coated gray
    cut off the welded 2-stroke motor mount

    shift kit:
    pedal cranks, motor mounts, sprockets, all power coated black

    engine mods:
    ngk plug
    stainless steel flex pipe with tip, overall lenght 28.5 inches.
    uni filter and adapter
    drilled out main jet with #71 drill bit

    image.jpg image (3).jpg image (2).jpg image (1).jpg

  2. jhammondcpa

    jhammondcpa Active Member

    That's a great looking package! I was wondering about the carburetor. I have a Phantom-Bikes Ghost 26 and have been upgrading it since the beginning of December 2014. I just added the AD Racing carburetor filter and have another carburetor about to arrive that will let me adjust the fuel flow. Did you have to adjust your fuel flow with your new filter? I have attached a copy of my new carburetor and a link to a YouTube page with a few videos I have posted of my two bikes. Keep up the good work!
    Left side .jpg ADA Racing Carb Cover installed.jpg

    Jimmy H.
  3. darwin

    darwin Well-Known Member

    KC, some times can be a pain. His adversisments can be annoying. BUT he helps folks and is a valuable asset to the community.
  4. aceinthesky

    aceinthesky New Member

  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    The adjustment screw is under the brass plug by the engine.
    Just drill out the thick plug to access the mixture screw.
  6. jhammondcpa

    jhammondcpa Active Member

    Thanks for the help, you guys are the best!
  7. jhammondcpa

    jhammondcpa Active Member

    I have been on that page, but I will look more closely! Thanks for the quick response!
  8. msiert

    msiert Member

    On that brass fuel mixture screw does it control the fuel mixture throough out the power band?
  9. jhammondcpa

    jhammondcpa Active Member

    You might want to write Terry Blow directly at Blow By You bikes at He has written extensively and posted more videos about these engines than anyone I have found to-date!
  10. KCvale

    KCvale Motorized Bicycle Vendor

    Just a tip for HS 142's, try an NGK 7544 (CR7HIX) Iridium plug before you start jetting.
    It's a tad longer than a stock plug for bit more compression and much better spark.

    Also note there is guy making offset intake pipes to use an NT carb on them.
    They work but not any better than the HS's carb but a good last resort if you can't find the right carb.
  11. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Was there a hole in the down tube after you cut the front mount off?

    Would love to see a pic of what the cut off mount looks like.
  12. KCvale

    KCvale Motorized Bicycle Vendor

    I haven't done one yet but I think if you cut the 2-stroke mount off at the angle and height it could support the bottom of a 4-stroke base.
  13. aceinthesky

    aceinthesky New Member

    The mount is welded over the frame. There is no hole, in fact you could patiently grind off the whole mount and have it as it was never there. I just cut it off near the frame and left the weld there because I did not want to chance weakening the frame by grinding it off. I'll snap a pic later.
  14. aceinthesky

    aceinthesky New Member

    here is the pic of the cut mount, its hard to see but there is no hole on the inside of the left over weld.

    image (4).jpg
  15. westmdrailfan

    westmdrailfan New Member

    aceinthesky thanks for posting the advice and the pic of cutting the two stroke mount off for four stroke use. 2?'s I have for you are what disk brake adapter are you using with your Skyhawk frame and did you use the headset bearing set that came with the frame or something different