new engine

Discussion in 'General Questions' started by tim85, Jan 3, 2015.

  1. tim85

    tim85 New Member

    Just bought a new 66cc engine kit. This is my second 66cc, and it is on the same bike my old one was on. Ive only ridden it for about an hour or so in total and while it runs, it does so in a slight jerking motion. This jerking motion gives me the impression that it wants to go faster, but it doesn't have the power. Is this common for an engine still in it's run in period? I cant remember if my old one used to do the same. Both had been slower during run in period, but the slight jerking I'm not too sure.

  2. darwin

    darwin Well-Known Member

    Jerking motion sounds like a clutch adjustment issue. How does it idle and rev up with the clutch pulled in?
    tim85 likes this.
  3. tim85

    tim85 New Member

    It idles like the choke is being used. If i leave it to idle the engine will stop itself before too long. It revs like it should and take off speed starts slow but it builds up smoothly.
  4. tim85

    tim85 New Member

    Could it be something as simple as fuel??
  5. crassius

    crassius Well-Known Member

    if the jerking is accompanied by a sharper 2-stroking sound, you might want to drop your needle to a leaner position to see if that helps - be aware tho that the engine will get leaner as it runs in, so be sure to check that it doesn't go too lean later
    tim85 likes this.
  6. tim85

    tim85 New Member

    There's no sharper 2 stroking sound. It should smooth out once it's run in more? I forgot to mention that it only does this at a cruisy speed.
  7. Timbone

    Timbone Active Member

    I would bet it is running rich at WOT. Chugging.
  8. tim85

    tim85 New Member

    Draining fuel and using a leaner mix will fix it up right?
  9. bluegoatwoods

    bluegoatwoods Well-Known Member

    No, I don't think so. They weren't talking about your gasoline/oil mix. They were talking about the fuel/air mix from your carburetor into the combustion chamber.

    That is adjusted on the needle that's at the end of your throttle cable inside the carburetor barrel.
    tim85 likes this.
  10. tim85

    tim85 New Member

    Oh yeah I get it. Moving the little e clip up a notch should do the trick?