Engine Trouble Engine problem, knock - wont turn over...[ bad block ]

Discussion in '2-Stroke Engines' started by i4tas, Jul 21, 2007.

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  1. i4tas

    i4tas Guest

    So me and a friend bought the exact same bikes and the exact same motor kits, and installed them side by side. One works great the other is having some problems.

    This bad one took more time start and took more time to find idle. It had this nasty engine knocking at low rpms but then went away with throttle. It would run but boggy and very chunky. Then it get hot after 10-20 minutes of ridding and dies. When trying to start it after this the engine won't turn over even with the clutch adjusted correctly. The clutch just slips and never turns over the piston. But the knock and poor engine performance is more concerning, which probably created the clutch problem.

    The knock or chunky engine movement seems to happen more when ridding now besides idle poorness.

    Any pointer, or advise would be great. I am stumped. The other bike works great and we have done nothing different.


  2. OldPete

    OldPete Guest

    Pull the exhaust pipe and inspect the piston...it might have seized.
    You gotta warranty? I hope.
  3. i4tas

    i4tas Guest

    What should I look for? I figure the obvious...

    One thing i forgot to mention, it seems that after the bikes sits for 10 hours and then is started again it will start and the whole problems happens all over.
  4. OldPete

    OldPete Guest

    It does sound like it is trying to seize.

    Look for scuffing on the piston or silver aluminum dust in the exhaust port.
    Use a strong light and look at the side of the piston carefully. Pay particular attention to the area around the piston rings.

    Take macro pics if you can and post them.

    Some of these motors do eat wrist pin bushings too and that might be in the mix.
  5. rcjunkie

    rcjunkie Guest

    The Chinese factories aren't known for quality. I have seen engines that were poorly assembled at the factory with missing parts. You should pull the head and cylinder and take a look at the piston. It could be something as simple as the piston installed in the wrong direction which caused a ring to break or it could be more serious.
  6. djase10

    djase10 Guest

    Hi, ya,
    Thats a shame to hear,
    But its good that you had the other bike there to rate yours against,
    But Yeah, a warranty is the go- Even if its only 30 days ,
    (like some here in Oz),
    that may be in your favor??
    Just try at the very least in any case>>..

    Good Luck.
    Regards djase10
  7. spunout

    spunout Member

    rcJunkie is correct. these companies that manufacture these really lack in quality control :x ...one motor off the line can be a screamer, and the next one right behind it goes woof! woof!
    use the warranty...quickly, too
  8. i4tas

    i4tas Guest

    The verdect is in! "seized"

    take a look at this:




    The last two pictures don't really show the damage, but it is there.
    The warntee might be a little harder for me as my supplier doesn't really do it.

    Maybe I will buy the replacement one from Dax, or if anyone can hook me up with a deal for just a new erngine I would appreiceate it. (I can mail the bad one back if a supplier can get me new one)
  9. azbill

    azbill Active Member

    yup ... you can butter that one...she's toast :shock: :shock: :shock:
  10. rcjunkie

    rcjunkie Guest

  11. That blows man. :(
  12. locoWelder

    locoWelder Guest

    200.00 paper weight :???:
  13. thatsdax

    thatsdax Guest


    You did not buy a Dax motor? oh nooo............. I have blocks for sale. These are updated with roller bearings !! O yes !!!
  14. i4tas

    i4tas Guest

    New Subject: High End Speeds

    Got new motor, runs great!

    One thing I noticed:

    the new one can go 30 easily with no vibrations, on the high end it the engine runs great no vibrations, it just kick in and goes faster, whistles but the engine isn't overheating or too high of RPM like you might notice at full throttle when idleing

    the first bike when going full throttle rattles at about 25 and the engine sound like the RPMS are too high and if you were to go at full throttle the parts would shake off.

    Since its the same two bikes and same engines how do I get the second one to kick in and put out on the high end of the throttle?
  15. impression

    impression Member

    wow, i have the reverse situation.

    my old engine, i didn't get a good mount ( rubber mounts suck ) was awesome, so much torque low>mid and all the way to full throttle. New engine has no guts whatsoever and has a whistle whining sound.
  16. V 35

    V 35 Member

    Hopefully, proper 2 stroke oil was used, I'd rock the con rod, to see if it moves freely.
    If correct oil was used, and crank is good, cylinder may have been poorly fitted at factory. Good luck on the Warantee, most vendors will try to pass it off as ' your problem, not mine ' Considering the lousy quality, vendors should be more receptive to factory fubars. The concept of tearing down a ' new ' engine, to see if was built right, is insane, but prudent. Before buying, ask vendor if they recommend a pre - fire up teardown, and if they honor warantee if [ when ] problems are found.
  17. dodge dude94

    dodge dude94 Member

    Not trying to be a jerk here, but this thread is 2 years old.
    Actually, older.

  18. FelipeCobu

    FelipeCobu Member

    Yeah someone deserves the Golden Shovel Trophy!