Lack of power/bursts of power

Discussion in 'Motorized Bicycle Trouble Shooting' started by D.Knight, Jun 10, 2017.

  1. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    And if you notice, since the arrow faces the exhaust port, the gouging occurs only where the cylinder blew up
     
  2. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Actually I'm wrong, unless I had the piston backwards. If I had the piston orientated right, the blowout would be on the opposite side of gouged area of the piston. But I pulled both pins out of their homes and they were seated properly
     
  3. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
    That's kinda normal looking for a 2-cycle, probably something else caused the failure.
     
  4. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
    The piston goes in with the ring gaps toward the intake so the ends of the rings don't catch on a transfer port.
     
  5. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
    The marks or symbols on the top of pistons mean little to nothing more than manufacturing identifications, always install the piston with the ring gaps toward the intake.
     
    D.Knight likes this.
  6. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
  7. KCvale

    KCvale Active Member

    Joined:
    Feb 28, 2010
    Messages:
    3,854
    Likes Received:
    6
    You don't line up ring gaps for heavens sake!

    I put one ring gap to the left of the ports, the other to the right of ports.
    There is nothing for them to hit that way, and the ring gaps are separated.
     
  8. crassius

    crassius Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    3,278
    Likes Received:
    27
    wondering if factory screw ups include putting in a second clip by mistake - or maybe dropping one in motor and not getting it out

    never seen a motor with clips that don't match
     
  9. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Well I didn't find a clip in there, just the expected large shard of aluminum
     
    #109 D.Knight, Aug 7, 2017
    Last edited: Aug 7, 2017
  10. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
    It may be just a piece of metal that was the same size as a clip that started the problem.
     
  11. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Sure was. You can see the area below the port blew out and caused the piece resting on top in the pic to do whatever it wanted inside the motor.
    20170807_190148.jpg
     
  12. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Hey does anyone know if I need to plug the circled part of the carb?
     
  13. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Hey does anyone know if I need to plug the circled part of the carb? 20170812_085151.jpg
     
  14. crassius

    crassius Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    3,278
    Likes Received:
    27
    not sure, but that looks like a bowl vent which would be open - take bowl off and stick a wire thru to see
     
  15. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    Yeah it goes through to the bowl
     
  16. D.Knight

    D.Knight Member

    Joined:
    Apr 18, 2017
    Messages:
    80
    Likes Received:
    1
    I just feel like if it was a vent it would have some kind of filter to prevent crap from making its way down into the bowl
     
  17. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,776
    Likes Received:
    35
    #117 Greg58, Aug 12, 2017 at 10:16 PM
    Last edited: Aug 12, 2017 at 10:25 PM

Share This Page