2 stroke engine diaignosis

Discussion in 'Lawn Mowing' started by fga, Dec 30, 2004.

  1. fga

    fga LawnSite Silver Member
    Posts: 2,449

    what do you think would cause this, on virtually any 2 stroke with a pull start?

    you pull on the rope, and it is very difficult to pull, the crank spins maybe one or two times per pull, very slowly.
    you then rmove the spark plug and it turns totally free??


    feels like it has so much compression..
    i thought it was flooded, but not the case.

    any ideas? :help:
     
  2. out4now

    out4now LawnSite Bronze Member
    from AZ
    Posts: 1,796

    When our trimmers had that problem the recoil was usually ready to break.
     
  3. fga

    fga LawnSite Silver Member
    Posts: 2,449

    what if the machine was practically new?

    and as you turn the crank, you can hear the pressure around the plug?
     
  4. grass_cuttin_fool

    grass_cuttin_fool LawnSite Gold Member
    Posts: 3,503

    Does it run at all? I wonder if something is in the exhaust port and got it blocked off so it cant exhaust, have you taken the muffler off and looked in that area?
     
  5. fga

    fga LawnSite Silver Member
    Posts: 2,449

    i was running yesterday.. today i can barely turn the crank with the spark plug in. :help:
     
  6. out4now

    out4now LawnSite Bronze Member
    from AZ
    Posts: 1,796

    It's new and having that problem? Yes, check the exaust for plugging. Strange. If it moves freely with the plug out then not likely overheated or warped.
     
  7. battags

    battags LawnSite Senior Member
    Posts: 608

    How new and what brand? Is this a warranty fix?

    Brian
     
  8. grass_cuttin_fool

    grass_cuttin_fool LawnSite Gold Member
    Posts: 3,503

    I was thinking also of a term mechanics call '' hydraulic's'' where the cylinder fills up with fuel and it is so much in that the piston cannot make its cycle. but you didnt mention any gas coming out when you removed the plug so I dont think its hydraulic's
     
  9. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,085

    Am I missing something....with the plug out there won't be any compression and hence it pulls easy..With the plug in it pulls hard....probably means that rings are dragging on cylinder!! Usually caused by running raw gas or some off brand 2-cycle oil. Put some Mobil 1 in the spark hole and pull it 200 times with spark plug out and then drain oil and see if rings free up. Put echo 2-cycle oil in at double rate and run for several hours.
     
  10. Travis Followell

    Travis Followell LawnSite Silver Member
    from KY
    Posts: 2,207

    If its new it should be under warranty. Take it to the dealer and let them fix it. Most likely it has too much compression and thats whats making it so hard to pull. I really don't know what would cause this. Thats why you should let the dealer check it out.
     

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