Echo cs-300 won't open up

Discussion in 'Mechanic and Repair' started by TRex, Feb 17, 2004.

  1. TRex

    TRex LawnSite Senior Member
    from DFW ,TX
    Posts: 487

    I bought an Echo cs-300 for cutting landscape timbers and a few small branches. The saw worked great for the first few tanks and then I was cutting some peices in the back yard and it stuttered a few times now it only seems to open to half throttle. The chain will stop if add any force to the saw while cutting.

    However the saw will rap out if press the purge pump. I am not sure if the carb is dirty or the fuel is bad or what.

    If any one has had similar problems please throw me some help before the saw gets thrown.
  2. SWD

    SWD LawnSite Senior Member
    Posts: 989

    As long as yopu have compression,it's a bad pump in the carb - about a one to two dollar repair.
    Remove the carb, completely disasemble onto a clean shop rag (not a dish towel or other 'stringy' rag).
    The pump and diaphram are usually located on the bottom of the carb, with the needle and seat on the top.
    Once the carb is apart, reasseble with the new kit after carefully probing all the orrifices (holes) in the carb with a very small gauge copper wire.
    Simply blowing out the holes isn't enough.
    Once you have blown out the holes following the probing, reassemble the carb and you are done.
    This should take care of about 99% of your problem.
  3. TRex

    TRex LawnSite Senior Member
    from DFW ,TX
    Posts: 487

    I understand where you are coming from SWD, but I have never even taken the filter cover off and have only made sure the screw was tight. HOWEVER, I needed it today to cut some timbers and the starter rope pulled through the handle with the knot still in it. So I started working on it and decided to take the air filter out to see if it would change anything and it rapped out like itr used to.

    Thank You for the help. I guess i just need a new filter.
  4. Master of the Lawn

    Master of the Lawn Guest
    Posts: 0

    You need to check the reed plate behind the carb. These models of echoes are known for getting junk in the reed valve and running wide open. I was a mechanic on these engines for 9 years, I've seen this many times. Be sure to keep your air filter clean. If you have a air compresser you can shoot some air down the carb to break off the dirt, this does not always work, but worth a shot, carb can be pain in the butt to take off and reassemble. Write back and let us know what you find.:D
  5. TRex

    TRex LawnSite Senior Member
    from DFW ,TX
    Posts: 487

    Master, The problem with this saw is that it will not open up to full throttle, it will only open to about half way.

    It opens up without the filter, but I can't cut without a filter because all that saw dust will fly straight into the carb.

    I found the air filter soaked in gas with a little dirt, but I sprayed the filter off with carb cleaner and it looked brand new. I did not realize that gas could keep the carb from getting air. I geuss you can only prime a couple three times before it gets to much fuel to pour out the carb.
  6. TRex

    TRex LawnSite Senior Member
    from DFW ,TX
    Posts: 487


    The saw went back down hill after using it about five minutes. I pulled the carb and cleaned it and checked the diaphragms to make sure the were not damaged, otherwise I just sprayed it with some carb cleaner. Then I took both the oiler and fuel filters cleaned them. I also cleaned all the dust off from everywhere I could and put everything back together.

    The first time it started acting up I pulled the muffler and bored and ported it to make a little more power and a lot more noise.

    After I put it back together before I even filled it with gas or oil I gave it a couple pulls and it started to my surprise on the second pull with out the choke on or any priming, it was also about 40 degrees in the garage. I filled it up and stepped outside and it started right up again. I pulled the throttle and it stuttered so I let off and let it warm up some and it idled perfect. I gave the throttle another pull and instantly was at full throttle. It had taken on a new life.

    I have yet to cut with it because my sons trying to take a nap and the wife would kill me.

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