K75 ZAMA Carb

Discussion in 'Mechanic and Repair' started by TripleT, Aug 7, 2010.

  1. TripleT

    TripleT LawnSite Member
    Posts: 24

    Trying to help a friend w/ his GT 200R Echo trimmer. Took it apart and found out it had been sitting about 2 years. Carb was bad varnished. Took it apart, cleaned it, cleaned it & cleaned it some more & then installed new kit. Cannot get it to run w/o choke almost closed, will not idle. The K75 carb has no adjustments that I can see (except idle). I wanted to dip it but it has plastic part. The kit came with what I believe is a new seat but not sure so I did not change it. With cleaner I blowed thru every hole on the thing at least 10 times. Still same thing. Any help would be appreciated.
    Ray
     
  2. TripleT

    TripleT LawnSite Member
    Posts: 24

    Update!! After doing more research, I got the plastic plug out covering the high speed jet. Cleaned it and got it to start. Now it will not idle. It runs at high speed but if you throttle it back anything under about 2/3 open it stalls. Does the plastic plug need to go back in place? It looks like part of it is the threads that holds the high speed needle in. I also leaked checked it by blowing cleaner around oll the gaskets while running, I had no change in how it ran. Again any help would be appreciated.
    Ray
     
  3. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    What is the carb type? C1M, C1Q, C1U, etc. It would seem that the idle circuit is blocked.
     
  4. BigFish

    BigFish LawnSite Gold Member
    Posts: 3,064

  5. TripleT

    TripleT LawnSite Member
    Posts: 24

    Sorry Dutch1 Its a RB16 Rotary Carb. And Bigfish I review that post earlier, its what help me deside to remove the plastic plug. I finally got it to run and idle. I somehow lost the roller guide and did not reinstall the new one from the kit. Once I figured that out it started purring. Do I need to do anything w/ the plug? I removed the entire plastic piece. Cannt see like I use to!! It looks like its part of the threads that holds the needle in place. Thanks for the help. This thing almost made me loose it.
    Thanks, Ray
     
  6. BigFish

    BigFish LawnSite Gold Member
    Posts: 3,064

    No,toss it.
     
  7. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    I would have told you to check the nylon roller if I had known it was a rotary carb. I have run into a few pieces that would not idle and upon disassembly found the roller had cracked and was laying in the chamber.
     
  8. TripleT

    TripleT LawnSite Member
    Posts: 24

    THANKS FOR THE HELP!!!! I'll gladely through it away.
     
  9. jase4tiff

    jase4tiff LawnSite Member
    Posts: 56

    I am having the same exact problem what roller guide are you refering to.. I have pulled and cleaned and pulled and clean. My zama has a brass cap over the idle adjustment I still havent removed that yet.. but your situation is exactly the same thing mine is doing so it may be that roller guide.. thanks Jason
     
  10. TripleT

    TripleT LawnSite Member
    Posts: 24

    Once you remove the plastic linkage throttle valve there is a metal pin sticking out as you look down into the carb from above, to see it you have to remove the plastic cable linkage first. The roller is about the size of #2 lead pencil and about 1/8" in diameter. Its real easy to loose, I did not even know I had lost mine until one showed up in the rebuild kit and I was not sure what it was. The roller will fit over this pin. Once put back together this will actually raise the throtle valve up some. This site will show you the roller, its item #21. http://www.ereplacementparts.com/ec...-grass-trimmer-parts-c-35043_35180_35289.html This site it will help understand how it operates. www.zamacarb.com
     

Share This Page