Slooooow ride

Discussion in '2-Stroke Engines' started by wildkeith, Jul 30, 2008.

  1. wildkeith

    wildkeith New Member

    Hey guys,
    First, thanks for the help I received in the past. I hope I can help other frustrated users once my problems are resolved.

    I've ran 3 tanks of fuel through my 48cc 2-stroke over the past month and I'm still riding at about 10-15 mph max. That's much better than the 8-10 mph max I was getting, but still frustrating. Going up the average hill almost always results in stalling out. I feel like I could peddle faster than this with ease. My town is all 25 mph, so this is really holding me back :???:

    Heres some info:

    1.After 3/4 throttle the engine doesn't seem to respond any better, in fact it doesn't sound quite as strong or peppy as it does at lower throttle. I guess this is what you would call bogging down. Is that a fuel mix problem?

    2.I've checked for intake and exhaust leaks. Nothing.

    3. I tried to set my idle screw to 4.5 turns, but the engine stalls if I turn it out more than 3. Could this be an indicator of my problem?

    What are the typical problems that could rob power that much? What do you think I should adjust? What speeds should I realistically be getting? Surely faster than 10-15 mph, right?

    Thanks :grin:
    Last edited: Jul 30, 2008

  2. BSA

    BSA Guest

    Have you tryed reading your spark plug?

  3. stude13

    stude13 Active Member

    hi keith; is the head tight?
  4. pedalpower

    pedalpower Member

    hey, akums razor here. is your throttle adjusted right? is it reving at full throttle? how high is it reving? are you running lights that might rob spark? bad CDI? regap plug?
  5. wildkeith

    wildkeith New Member

    Hey, I attached a couple pictures of the spark plug. I can't tell which chart picture it matches best. The head is tight. The throttle is adjusted correctly. No lights. Don't know about the CDI. Does the gap look okay in the photos?

    Thanks guys! :)

    Attached Files:

  6. BSA

    BSA Guest

    Your engine is running too lean. Have you tryed checking for an air leak. if your confident that there are no air leaks try moving your c clip u the carb's needle. Try using the bike with the choke in.

  7. Scottm

    Scottm Guest

    Plug should be gapped at .028 plus there are better plugs and wires, but stick to basics for now
    Keith forgive me for going OT or hijacking. I need a lesson from BSA.
    BSA Since I know little about this could you please explain how you can tell it's running lean? Does lean mean too much air and too little fuel? The plug looks dry and "burnt" rather than moist. Am I close?
    Last edited by a moderator: Jul 31, 2008
  8. BSA

    BSA Guest

    A lean plug will be dry, a grey sort of colour and may have ash. If it's a toasty brown your running good, if it's black and wet your running rich.

  9. Skyliner70cc

    Skyliner70cc Active Member

    Could be anything. Did you follow many of the build tips on this forum? could be a partially clogged filter in the petcock valve (it should be removed and an inline fuel filter used instread). It could be to rich or too lean mixture. Fiddle with the choke while at full throttle and if it starts picking up, it means you are too lean. If it gets worst while fiddlign with choke, it means you are ok or too rich.

    It could be an OEM spark plug-chuck it in trash asap.
  10. Gimmick

    Gimmick Guest

    I bought a grubee round head 48 cc once that did the same thing, it would rev fully under no load, but under load it would only go tops 17 or 18mph, I finally just gave up on it, it could have been ported wrong, or had something defectvie in it, i used it for clutch parts and covers/gaskets...