worked fine last night

Discussion in '2-Stroke Engines' started by kcmcf, Aug 29, 2008.

  1. kcmcf

    kcmcf Member

    ok i went to go run some erans today and it wouldnt start. it ran fine on the way home last night.

    i have done all the usual, has good spark, changed any way, checked fuel good fuel. just mixed up some 2 days ago. took off kill switch and white wire light still no go. took every thing off and re sealed everything took the kids carb off and put mine on his started right up on his. checked clutch it is good.
    it just spits and sputters dosnt want to run at all. i am all out of ideas. any thoughts besides a stick of dynomite. LOL

  2. QuadManiac

    QuadManiac Member

    With "good spark"???
  3. fetor56

    fetor56 Guest

    Strange that it ran fine last night & now it doesn't....has something happened since then(eg,was it rained-on overnight/is the fuel contaminated)
    If there is no obvious explanation i'm afraid it's gonna have to be trial & error....your doing the right thing by swapping parts.
  4. fatboy67

    fatboy67 Member

    May be the muffler has some thing blocking it.
    Just a thought.
    If you have spark and fuel then the next thing is compression isn't it.
    Or may be like Large said the "Magneto" may be you get some spark when checking it,, but when the magneto is under load it may not function fully.
    Try you sons magneto.
  5. kcmcf

    kcmcf Member

    didnt get rained on i keep them in the garage, i am going to swap mags and cdi's today and see if that works. i did swap carbs yesterday and took my sons bike it is working great. also going to pull the muffler i just built a new baffle for it a few days before it now has 3/4 pipe coming out instead of the oem one. have to take something pritty big to plug it.
  6. For Poops And giggles.

    How's the plug look?" wet Dry.Compressions good.?

    Do you hear the motor Going up and down when trying to start.

    Sorry to ask that question but Here at Blue-Collar We get many phone calls regarding the same Problem and their clutch was not engaging All the way to turn the motor over.

    You seem very knowledgeable ,,so I'm sure she's Turning over fine.


    Why not give a little squirt Of starting fluid.

    I said little. lol



  7. kcmcf

    kcmcf Member

    yes its is engaging, i have swaped the cdi and mag from my sons bike it helped some, wants to fire then high idles then dies i have taken the baffle out, draind tank taken out petcock all are clear same with the filter. all out of ideas.

  8. sounds like Air leak. check intake manifold and carb for leaks.

    Also take off the air cleaner Look to make sure Slide is not in the up position.


  9. kcmcf

    kcmcf Member

    all ready did
    also put in new o ring
  10. how is the Compressions?

    whats the plus saying..wet dry??

  11. kcmcf

    kcmcf Member

    a little wet from me trying to start it.

    compression is also good, i took the head and cylinder off yesterday just to be on the safr side every thing looked fine to me no scoring and rings look good.
    Last edited: Aug 30, 2008
  12. If you have Good compression A correct and uncontaminated Mixture.

    And their are no air leaks With a correct operating exhaust .
    We need to focus on spark plug..And wire.kill switch.
    CDI & mag.

    You did disconnect Kill switch and tried....correct.?

    Also you may give Us A call .( this typing is getting old) LOL

    I know the Motor kit wasn't bought from me but i don't mind helping at all.




  13. You seem to know your Poop.
    If the Motor runs on Starting fluid Low compression is not yet ruled out. air being sucked by the crank seal will give a high Rev symptom as well.
    recheck manifold gasket..

    It sounds Like A Air leak ( might be coming from crank ) .

    Ill keep thinking.
    Let me know the outcome.


  14. QuadManiac

    QuadManiac Member

    Blur Collar - I'm new to MB's but have been around IC engines for many years. Here's something I learned from my 2-stroke outboard motor days - using starting fluid (usually ether) washes lubricant from the exposed surfaces and can contribute to unexpected ring and cylinder wear; for 2-strokes it was always recommended to use a spray bottle with the proper gas/oil ratio to inject a test starting mixture. Do you think the same issue would apply with these motors?

    BTW, in this case I would have guessed intake manifold gasket... but didn't think about the crank seal. Not something that would have been an issue on outboards. Good place to look. If you can get to the crank seal while running, spraying some 2-stroke oil on it will make a temporary seal, if idle drops to normal briefly, you know it's sucking air.
    Last edited: Aug 30, 2008
  15. kcmcf

    kcmcf Member

    found it it is the crank seal the one behind the primare drive gear. pulled the clutch cover off and put my hand by it as i was peddling puff puff puff right out the side.
  16. Bummer..

    Wish i was wrong.
    I never had to replace one on the china Kits.
    Like i said on the phone .I ran into this a million times On older 2 stroke motors.
    It will not be an easy fix But it can be done.

    Sorry i don't carry any Seals ..

    If i did i would mail you one out for free.
    Try getting a hold of the original motors vender.( BGF)

    Crank seals can go anytime But having only one months On the BGF motor maybe he can give you a Kit or long block for cost.It never hurts to ask.

    Good luck

    Cheers :smile:

    Using Starting fluid can be very bad for a motor.I don't like it at all.
    But in situation like this It can pin point a Problem very fast.
    using starting fluid id a bad thing..
    Buy to a trained individual a small amount under certain conditions Will be fine.


    Last edited: Aug 30, 2008
  17. fetor56

    fetor56 Guest

    A stinking crank seal........well well that's about the last thing anyone would have thought of.
  18. your right !
    it was the last thing i could think of.

    Dam Murpys Law.


  19. Bronzebird

    Bronzebird Member

    Bravo Blue Collar!

    Crank seal just went over night and that seems strange to me. I'm milking my break-in on my first HT and am learning alot from you guys!
    For what it's worth, thanks ALL.