Echo trimmer---what have i forgot.

Discussion in 'Mechanic and Repair' started by themow, Jul 24, 2008.

  1. shepoutside

    shepoutside LawnSite Bronze Member
    Messages: 1,208

    You probably need to dunk clean the carb, but you need to find a place that iodizes, or uses the water dunk, not the solvent dunk. Some small engine places that are bigger will have one. You should not use solvents as there are internal seals.
  2. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293

    I agree on the seals being unlikely.

    After thousands of tune ups in my shop, we never identified an echo seal or bearing to be bad.

    I am sure it happens, but it is rare.

    I am surprised that feathering the choke did not improve the performance.

    If the motor is worn on the lower end, it will run while warming up, but run very poorly when hot, or quit (then will not start till cool).

    The exhaust and the fuel filter have been eliminated as a problem. I assurme it is running lean. If it is running rich, the exhaust will be smoking much. Almost all fuel problems on the small 2 cycles is a lean condition. Post a reply if running rich. Below is what I would do if running lean.

    I would adjust the only needle available to the left no more than 1 full round (than it is at present). If this does not solve then the most common solutions are below:
    Rebuild carburetor - replace; diaphragms, carb screen, needle and metering lever, purge pump bulb.
    Place plastic under purge bulb as posted earlier. This prevents air entering through bad duckbill valves. I am running 4 trimmer motors. Three are very old (1500+ hours). I have blocked off the bulb on all three.
    Replace gas hoses. They sometimes get tiny cracks.
    Check for an air leak anywhere going to motor and crankcase. All gaskets, crack in plastic manifold from carb to motor. I use a spray bottle of water and spray while it is running. If the motor dies as I spray it, I know the area sprayed is the place of the air leak. The gas tank vent (on the end of a fuel hose, white in color) can cause a lean condition, but only after a while. A vacuum must be created in the tank first.
    If all fails, try to find a echo with a known good carb. Place it on yours. If this solves the problem, then your carb is bad.

    Good luck
  3. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293

    I missed a post you made saying it is smoking. This indicates it is running rich (or very bad and old mix). There is the possibility that the metering lever may be bent too high which allows too much fuel to enter the motor. The easy way to determine the adjustment on them is to get the lever level with carb housing. Depress the lever. As you depress it, the needle will rise. The lever should be depressed 1/2 of its travel before the needle begins to rise.

    If the needle lever is bent too high, place pressure with small screwdriver on top of the needle end, while pressing (with another small screwdriver) the other end of the lever.

    Good luck,
  4. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,588

  5. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293

    My "expertise" is quite old now. I had a shop for 10 years from 83 to 92. I sold Echo and other brands of saws and mowers. Our repairs of all units per month was 600 (mowers, motors, trimmers, chainsaws .....). For the past 12 years I have been doing tree work and using about 15 different echo units. (The blowers and extension saws have the same 21cc/24cc engine as the line trimmers) I have not seen many of the newer models. The quality of the seals and bearings may have changed.

    About the external carb adjustment needle. This would be the low speed adjustment while the high speed would be preset with a fixed jet. If the high speed jet is partially clogged, you will probably have to find a shop that can clean it.

    It was my impression that you wanted to repair it cheap, so the prior posts and this have some tricks I have used in and out of the shop. I live is a small west Texas town without a convenient source of small engine parts. So many repairs have to be done with the old part or used parts.

    About bending the metering lever tab. Our old chainsaw mechanic taught me that. It really helps on starting. You will find that many new levers travel 3/4 of the distance before they open the needle. And if the old lever has to be used, it will be worn and bent ever so slightly causing the same condition. There are few carbs I work on that I do not bend this lever. I only observe the metering needle when doing this.

    I hope this helps and shows you my perspective. I certainly did not mean to leave the impression that I am the "WORD" on echo. Some of these are just alternative repairs that I have done many many times and they have worked for me.

    I hope this has been helpful. I believe most all of it can be used on 90 percent of the 2 cycle saws, trimmers, etc. regardless of the brand.

    Good luck

  6. lubricity

    lubricity LawnSite Member
    Messages: 125

    Take a compression check and post what you got
  7. themow

    themow LawnSite Member
    Messages: 41

    I took a compression test today. It read 110 psi. I have been using it as is. Fine for smaller stuff but not enough poweer for thick things. The trimmer was made from 86-88 and it has 2 rings. When i initially pulled the exhaust and the spark plug off i found lots of carbon. I thought that maybe i had a stuck ring but i guess thats not the case.
    When you block off the primer bulb, is it due to a lean condition. I dont believe its running lean due to the excess smoke although it is a bit hesitant to rev down which i know to be a trait of running lean. Im fairly convinced its a carb problem but i dont want to invest in a repair and rebuild kit if the inner seals are shot.
  8. punt66

    punt66 LawnSite Fanatic
    Messages: 8,536

    Thats an old machine, invest in a new one. there not very expensive.
  9. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293

    Surely someone has suggested cleaning the exhaust port and removing the spark arrestor screen
  10. lubricity

    lubricity LawnSite Member
    Messages: 125

    $55 is the cost of a piston kit, (piston, bearing, two washers, 2 clips and a wrist pin). while you have it apart clean the passages that run in the side of the cylinder and exhaust port thoroughly, and scuff the cyclinder with some emery cloth. Clean everything thoroughly. Put it back together, it should work.

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