what to upgrade next?

Discussion in 'Performance Mods' started by Mike Hunt, Nov 28, 2009.

  1. Mike Hunt

    Mike Hunt Member

    i got a stock 50cc happy time, gutted muffler, no headgasket, upgraded sprocket mount, stock carb. i have 200CAD that i can spend on upgrades. what would you do?

  2. AussieSteve

    AussieSteve Active Member

    Expansion chamber or high-compression head.
    Maybe get your stock head shaved, (milled) and buy an expansion chamber. If there's still change, get a better carb - CNS, Dellorto (clone) or Mikuni. Rock Solid Engines sell the Dellorto clones and Mikunis.
    A sheet of glass with wet & dry paper on it, along with lots of time, will mill the head if you're careful to keep it flat. Shaving the head 1mm will dramatically boost compression, therefore power, else buy a slant head. The stock head is 6.5:1, I believe that the slant head is about 8.5:1. The Rock Solid Engines billet aluminium head is higher still.
    In the meantime, open up your inlet tube and gasket at the cylinder end to more closely match the port and do the same with the exhaust and ensure that your carb is sealing well.
    If you search, you'll find heaps of posts covering these topics pretty thoroughly.

    ... Steve
  3. HI,

    Best bang speed wise is a smaller sprocket....

    Hope this helps you.

  4. Hajuu

    Hajuu Member

    Stick on a cowbell. Everything needs more cowbell.
    miketaco, Timbone and HeadSmess like this.
  5. Crobo

    Crobo New Member

    your best bet would most likely be an expansion chamber and carb. not sr about the CAD to USD conversion as of right now but you should be at about 150 USD
  6. Usaman303

    Usaman303 New Member

    Lol THIS GUY knows what's up. For real though, the best bang-for-the-buck upgrade for me was a "racing carburetor". You know, the deal you'll find on pocket bikes. I got one that included the proper throttle cable, 5 different jets (technically six) ranging from 60-80, and never looked back at the NT garbage again. Don't get me wrong, if simplicity is your goal the NT wins every time. BUT if you know how to tweak a carb, you can really open these engines up and let them breathe. Plus the option of changing jet size will really help your bike run better depending on where in relation to sea level you're riding it. The NT has a 70 jet if i'm not mistaken, and other riders in my area swear by 62 jets, so there is a little difference there. Also, forget about leaks with this carb. Delrin bushing keeps everything air-tite.

    Oh yeah, if you do go with this upgrade let me know before hand and I'll let you know where to get a deal. I got mine for $40 shipped to my door (which only took a day and a half from the time I ordered it) with the cable & jets. I'm told that if you pay more then $35 for one of these and it doesn't include jets and cable, you're getting ripped off. I'm also not trying to sell anything to anyone either, so please don't think that. I'm just speaking from personal experience.

    Edit: I said technically six jets because there were 5 bags labeled 60, 65, 70, 75, 80, all containing a jet (in the package that arrived). When I took the carb float bowl off to install my preferred jet, there was already one (of unknown size) in there.
  7. wheelbender6

    wheelbender6 Well-Known Member

    Exhaust expansion chamber and Dremel tool. Use the dremel to clean up intake and exhaust ports, inside of the intake and you can port match the exhaust flange.
  8. BikerDog

    BikerDog New Member


    for sure more cowbell haha
  9. jaguar

    jaguar Well-Known Member

    You can create more engine compression for a notable boost in power with just a piece of thick glass and some sandpaper. Use them to plane down the cylinder head and to resurface the cylinder top.
    You can boost your low rpm power with some simple tubing between your engine and your carb. (get a better carb first)
    Increasing your engine size to 55cc only costs $75.