help! New 49 cc chinese shuts off after bout 12 min of riding

Discussion in '2-Stroke Engines' started by yimmie, Sep 26, 2009.

  1. yimmie

    yimmie Member

    my new 49 cc chinese 2 stroke shuts off after bout 12- 15 min of riding? if u try giving it gas , even with clutch engaged it bogs and dies? works great for that first 12 min. any1 help?

  2. bigdan

    bigdan Member

    Does the engine die suddenly: like you're whizzing along and then it just dies or is it a gradual loss of power until it won't run? How long does it take before you can start it again? Does it make a difference if you use the choke? Have you checked for spark?

    A sudden loss of power sounds like an ignition or electrical problem. If it's more gradual, it's probably air/fuel related.
  3. I'm experiencing the same thing. My engine has been running awesome for three weeks and has maybe 200 miles on it. Yesterday I made some mods and now it runs awesome for two or three minutes then dies. Sometimes it will re-ignite if I work the throttle but run erratic and then really die. If I wait a couple minutes it will fire right back up. In fact, it starts better than ever even with very little choke initially and none when it warms up.
    Here is what I did. I added expansion chamber/tuned pipe, new plug wire, and new plug. As for plugs I have a DiamondFire e3.12 and a NGK bp7hs. Both plugs produce same results. I also took carby apart and everything there seems normal. Taking fuel line off carby and opening fuel valve gives steady flow.
    Not sure where to go next but I'm guessing to try a new CDI or would like to hear any suggestions.
  4. spad4me

    spad4me Member

    It sounds like you have loose debris (****, junk, dust ) in your fuel tank or float bowl maybe lodged in your jet even.
    When you let it sit it settles when you ride it goes into suspension and clogs stuff up.

    Drain your tank, clean your jet with a fine wire. Install a new fuel filter.
    If this does not work, did you wash the bike or get rained on.
    Moisture turning into steam and condensing on your electronics. will stop you after awhile too.
    Both have happened to me.
  5. Fixed it. I cut out the kill switch wires and just rode for about 30 minutes with not so much as a sputter. Now I just lower the idle setting till the engine dies as choking didn't kill it. No biggie cuz I constantly am adjusting idle anyway.
  6. yimmie

    yimmie Member

    thanks for all the input. i may have fixed my problem, i believe it was choking out. not enough air flow. stock air filter and foam element. i swapped them out for a kustom ram air setup. seemed to have fixed my problem. we will see!! but the bike runs much better, and the ram air seems to be making a difference.