Engine will not wind out

Discussion in '2-Stroke Engines' started by Timbone, Feb 8, 2015.

  1. Timbone

    Timbone Active Member

    It seems like ti was not so long ago that my HT engine would want to wind up to infinity. Not the case anymore.

    I've solved my motor mount issues, developed a bombproof fuel line with 1/4" stainless steel tubing, and the high mileage 2 stroke motor does like to run, but it will not wind out. It runs well, very smooth at WOT, but I am finding a steady cruise of about 22mph. That's all I get. And it is not real torquey.

    My FEELING is that it's not getting the fuel flow it needs to wind out.

    Here are the symptoms:

    1) Motor usually takes more than a few attempts to start when cold. It helps to do a lot of pumps on the primer button. My sense is that the engine is not pulling fuel into the cylinder properly. I removed the float bowl from the carb and there was plenty of fuel in there. I tweaked the copper tangs upwards just a touch to raise the float level.

    2) Applying choke when starting doesn't really help.

    3) Spark plug (NGK B6HS) looks pretty black and carbonny, so it doesn't seem to be running lean. There's no smoke coming out of the muffler and it isn't bogging down at WOT, things that would indicate a too rich mixture.

    4) I don't think this is an airflow issue. But what would it look like if the engine needed more air to run higher RPMs and they weren't there? I would think it would be a surging/bogging down thing and I am not getting that.

    Signed perplexed,


  2. jaguar

    jaguar Well-Known Member

    try running it without the air filter to see if that is too restrictive.
    if you run higher speed then buy a filter that doesn't restrict flow.
  3. Timbone

    Timbone Active Member

    Thank you, Mr. Jaguar. I did this; no real effect. I have a good air filter. I've been amassing all kinds of good filter material.

    I think I have figured it out. It's just running rich. I can adjust to this at cruise: I placed a needle valve as my petcock. I can actually control the mixture by hand on the fly. This is a good engine; it just wants to go. It's cruising again at about 25mph.

    But the hard starting is still an issue. It's either getting too much fuel at start or too little. Once it kicks I am good, very nice idle on this. Sometimes I can press the plunger about a dozen times and it will start right up. Then the next time, doing the same thing, it might take 15 attempts before it starts.

    Oh well.

    Thank you!
  4. jaguar

    jaguar Well-Known Member

    the stock carb does not have an idle circuit so starting "not easy" is to be expected. I recommend putting a good carburetor on it. look at my site.
    Timbone likes this.