Very low torque?

Discussion in '2-Stroke Engines' started by geebt48cc, Aug 18, 2010.

  1. geebt48cc

    geebt48cc Member

    Hi room,

    Uno, the 48cc Skyhawk does fantastic considering it's HP. Tops are good, Mids are ok, but it takes it till about 15+ mph before it can even come close to gaining any torque for even a smaller grade?

    Miles total now are 250--(25:1)---Ok, its got NGK's (Tan in color),expansion chamber (SBP),air filer (SBP) ,new cap and wire, on second notch of needle,everything lubed + tight.:confused:

    Any ideas? See, the reason I am confused, is because at times its had a lot more pull. Top end on flat is 30+.......


  2. AussieSteve

    AussieSteve Active Member

    Glen, there have been a lot of discussions about increasing bottom-end. The best thing is lower gearing, or, to have the best of both worlds, a shift-kit.
    Mine was much the same and had no guts below about 15mph. The shift kit cured that.
  3. geebt48cc

    geebt48cc Member

    Yeah Steve, how come I knew you would say that. True, I went about 20 miles today, and everything is hanging in there...............But, it's really not much to talk about from 0 to 15 ish MPH?

    Ok, Now, tell me where I should start with shift kit. (SBP)?

    Thanks, Glen

    PS-Still cold down there????
  4. AussieSteve

    AussieSteve Active Member

    If you decide on a shift kit, definitely go with the one from SBP. A bit more expensive, but far higher quality. I'd recommend the HD or Deluxe HD kit. The heavy-duty freewheel is a must.

    That was the main reason I fitted the shift kit on mine. I had a bad fall on gravel due to too high a gearing ratio. Now it's got lots of low-down pull and I can putt along at 5mph comfortably if I want.

    A longer header on the expansion chamber might help, too.

    Yep, still cold here but it's just starting to warm up. Quite pleasant in the middle of the day. Almost an early Spring - Sun's shining, birds are singing...
  5. geebt48cc

    geebt48cc Member

    Thanks, I'll do just that about the shift kit.

    Steve, with the expansion chamber, you do mean the first straight copper pipe that leads out from the bolted on black header. Wonder how much longer that would help? Oh, and Steve, where should I go to get a few more c-clips for carb needle? I've tried a few places and everyone scratches their head, and says, "**** that's small..........!"
  6. GearNut

    GearNut Active Member

    Hobby shops that sell model air planes, cars and boats should have plenty of them.
  7. skrufryder

    skrufryder Member

    I got a couple kicking around if u want i can mail you a couple
    send me a message with info to send them
    Last edited: Aug 18, 2010
  8. AussieSteve

    AussieSteve Active Member

    Yeah, Glen, just the straight part before the pipe widens. All the same, you won't get much improvement. With 2-strokes, unfortunately, it's the nature of the beast to have no low-end torque, especially a ****y little 48 or 66cc.

    You might have trouble getting 'C' clips on their own.
    You can get a needle with clip for $3.99, though, from ThatsDax, here.
  9. geebt48cc

    geebt48cc Member

    I took yesterday..................after right around 20/miles

    Thought you would better see what we are working with:)


    Attached Files:

  10. Chalo

    Chalo Member

    Have you ever driven a standard transmission car? Well your bike only has 4th gear, unless you use something like the Sick Bike Parts shift kit. And a two-stroke engine has a peakier powerband than a car's motor-- that is, it has to be turning at least a certain RPM before it really gets to making good power.

    The moral of the story? Your bike has pedals. Use them to help the motor get up over the RPM hump.

  11. GearNut

    GearNut Active Member

    If it likes to run with the choke on a little bit, that is a sign of an intake leak or lean air/ fuel adjustment in the carburetor.