Noob with HT Not Happy

Discussion in 'General Questions' started by SchwinnHS, Jun 19, 2008.

  1. SchwinnHS

    SchwinnHS New Member

    I installed a HT on my Schwinn Mountain bike and was riding and having fun for a couple weeks but started having problems getting the thing started. I have verified I have spark, fuel (with air), and compression. I also use the 20:1 ratio mixture with premium gas. I had some backfiring after about a 35 minute ride and thats when my problems started. Could this have damaged the carb. The fuel bowl looks ok but I can smell gas in the cyl and plug. Seems like it's flooding quickly. Anyone out there experience this?

  2. Alan

    Alan Member

    Plug isn't fouled ? Have you tried regular grade fuel ?
    Getting back to the plug, they are manure, and can fail. Try a new NGK.
    Air filter OK?
    Screw approx 4 turns out ?
    Working, clean, in-line fuel filter ?
    Last edited: Jun 19, 2008
  3. Simonator

    Simonator Guest

    Well, first off, Premium gas is an overkill. You are just wasting your money. 85 - 87 octane is plenty for our low compression engines. Have you adjusted the carb at all? What is your spark plug gap? I don't think a little backfiring is going to hurt the carb. Also make sure there is no vacuum leaks in your intake. Let your engine completely warm up, then use the choke to see if it stalls. It should stall right away. If not, you have a vacuum leak somewhere.
  4. bluegoatwoods

    bluegoatwoods Well-Known Member

    I'm no expert, so I can't offer much. But you mentioned that you have fuel, air and spark.

    That should mean a running engine. If not, then I would suspect that your spark is intermittent. That's where I'd be looking.

    Good luck.
  5. SchwinnHS

    SchwinnHS New Member

    Yea its the weirdest thing. I think I have removed the carb from being the problem. I verified spark with a new plug gapped at .034. Just grounded it against side of motor and cranked. I'm getting a nice little blue spark. I sprayed some engine starter directly into the cyl and screwed the plug and cranked away. I figure i should atleast get a pop or something. Nothing. Could i have wrecked the timing somehow? Getting ready to take the thing aprt and start over.

    Oh and thank you all! I finally found this place after thinking I was all alone out here. Its nice to be part of the group. This site has everything you need to know to get motorized!

    Dave - Albuquerque
  6. HoughMade

    HoughMade Guest

    Do these things have a key on the output shaft? If so, it could have sheared with the backfire. I know engines, but I don't have a HT.
  7. Spark apparently isnt your problem but .034 is too wide a gap for the spark plug. I would gap somewhere between .020 to .025 There is a key on the magneto and if it sheared and moved partially that would change timing, therefore the backfire...
    Last edited: Jun 20, 2008
  8. SchwinnHS

    SchwinnHS New Member

    I really don't know enough about the motor to answer that. It looks like there isn't a key from what i can see without opening the crank case.
  9. SchwinnHS

    SchwinnHS New Member

    Yea, There is a tiny key on the magneto side of the output shaft. It's still in place so my timing should be ok hopefully.
  10. SchwinnHS

    SchwinnHS New Member

    Those darn spookytooth instructions say to gap at .038 I will get another plug and try .020 to .025. I'd rather be riding! Thanks again
  11. KiDD

    KiDD Member

    I had my Champion CJ7Y plug gapped to something like .06 and it worked... but I set it down to .03 just cause thats what everyone says is good.
  12. Accender

    Accender Member

    Flood the gates with gas mixture. She will start.
    From what you said, ( I think) shes starving for gas. Or your timing is 180 out.
    Meh~ dont listen to me.

  13. SchwinnHS

    SchwinnHS New Member

    I'm back on the road after a few problems. I replaced all the gaskets and regapped to .026 or so and it started up. Must have been a combination of low compression and intermittent spark. I rode a couple days and snapped my frame. Jumping curbs wasn't the best idea. I just had it welded back together and im back in business!

    It does take a bit to get it started when cold but once it warms up it does fine.

    Thanks again everyone!
  14. Using the choke might help get it started easier when cold. just have to play with it to find best position for starting.. Here in Florida very rarely need to use it....