Question re power loss on recent ride

Discussion in '2-Stroke Engines' started by dbertoncello, Aug 7, 2008.

  1. dbertoncello

    dbertoncello New Member

    I recently acquired a Dahon folder with Mitsubishi 42cc (?) motor, Dimension Edge friction drive. Motor has about 15- 20 hours on it. Was riding along and experienced power loss with half tank of fuel still remaining. I was mostly powering and occasionally pedaling. The motor would not restart so I pedaled on home, filled the tank up full and the bike started and ran fine. Does anyone know what would have caused the power loss, it just kind of bogged down to a halt, when it happened. I thought these two stroke motors just keep on running as long as they have fuel. I use a 50:1 fuel ratio which is recommended. Any thoughts or suggestions would be appreciated.

  2. stude13

    stude13 Active Member

    hi bert; it sounds like your gas cap isnt vented. if it happens again remove and replace gas cap. it has happened to me on a car. mitch
  3. 50:1!!!!!

    for all and i mean ALL two strokes the best ratio is 28:1!!
  4. dbertoncello

    dbertoncello New Member

    Thanks Mitch, Ill give that a try
  5. dbertoncello

    dbertoncello New Member

    Can you give more detail regarding why this ratio. Thanks!
  6. Skyliner70cc

    Skyliner70cc Active Member

    If more oil is better, than why settle for 28:1, I say kick it up a notch and go 16:1
  7. Esteban

    Esteban Active Member

    I am pretty sure that 50:1 is recommended in the manual. I , MYSELF , would not deviate much from that. Are you using a good quality oil ? Try changing the plug ?
  8. dbertoncello

    dbertoncello New Member

    Here's my symptoms, what's the cure??

    Here's a little more detail on my previously posted problem concerning my Mitsubishi 43cc two stroke. It is a relatively low time motor from previous owner, about 15 hours or so. Driving a Dimension Edge friction drive. Motor starts fine and seems to run smoothly, but after a short time bogs down almost to a stop when powering the bike. I'm not running it real hard, when I open the throttle, you can hear a 'whaaing' sound from the engine as if it is trying to get more gas, but doesn't produce power then just bogs down and quits. I'm using the recommended 50:1 ratio, two stroke oil, spark plug seems clean and right color, gas cap appears to be vented. Peddle on home and it starts right up again, just won't last for long under power. A mechanical mystery to me but not to one of you fabulous gearheads. Any other suggestions along with the previous ones will be appreciated. All I want to do is have some fun with my new toy!
  9. BoltsMissing

    BoltsMissing Active Member

    Is air flow to cylinder/head fins and carby restricted ?

    Can you post some pics. so we might be able to see if that might be the case ?
  10. machiasmort

    machiasmort Active Member

    if the idle wavers up and down while idling (standing still) check your carb float and make sure your gas cap breather is working!

    Only when driving (asking for power) check fuel filter,air filter and then for vacum leaks arround the heads ect.
  11. dbertoncello

    dbertoncello New Member

    Thanks to all for your suggestions. I'll check on those items. Standard Dimension Edge install, no obstructions to airflow.
    I really appreciate this forum and for your assistance!
    Thanks much!
  12. machiasmort

    machiasmort Active Member

    try checking the float bowl level. the little bowl that holds gas before going into the cobustion chamber might be running out to fast because the inlet needle is stickig or the level is set to low. Kind of like a toilet not flushing out because the water tank is low

    Also check for vacum leaks near the carb baseplate. Let me know how things go.

    Sure hope this guy you got it from broke it in properly!
  13. Ozi

    Ozi Member

    Will it start again after it just stopped ? or do you have to wait till it cools down ?
    like you said 'peddle home' (cools down)

    sounds like some part of the ignition circuit is heating up, reducing spark and then getting to a point that it produces no spark (hot)
  14. dbertoncello

    dbertoncello New Member

    Seems to die down when I need it the most, eg heading up a hill. It will bump start with the friction drive but then not respond to full throttle. By the time I get back home it starts right up and runs fine again. I'm in process of checking all the suggestions, thanks very much for you ideas. Much appreciated!