Echo PE 200 & SRM 210 Low Compression

Discussion in 'Mechanic and Repair' started by Oli, Apr 13, 2014.

  1. Oli

    Oli LawnSite Member
    Posts: 39

    I acquired an Echo PE 200 edger, serial# 09016715, and a SRM 210 trimmer, serial# 08308360 from a customer for some work I did for him. They were both non- runners, but appeared in good condition, used only for his modest size yard, and garage stored for several years before he gave them to me. Both units have the same engine and exhibit the same conditions. The fuel lines were deteriorated, and there was no way to test them by simply putting gas in the tank and trying to start them. They did fire and run when gas was dribbled into the carb port. A compression check revealed only 90 psi for each unit. 110 psi or higher has always been my preferred number. The tester has a schrader vale in the tip, and has proven reliable in past use. An inspection through the exhaust port showed heavy carbon deposits on the top of the cylinders and around rings for both units, but no scoring. I concluded that the rings were sticking, and that new rings would increase the compression.

    After cleaning the carbon from the pistons, installing new rings, and cleaning the cylinders; compression for both units is still 90 psi. Once again, no sign of scoring on the pistons or cylinders. Both units fire and run when gas is dribbled into the carb port.

    Is 90 psi compression adequate for these units? I would like to know before I spend any more time or money on them. Thanks in advance.
     
  2. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,533

    Take a tea spoon of 2 cycle oil and pour it into the cyclinder, do not put the spark plug back in, cycle the piston a few times to get the oil around the rings and on the cylinder. It's messy, cover it with a rag or something. Now check your compression, if it hasn't come up....

    Well, it's a judgement call if you want to spend more money and time on them. You could buy a new one for what the parts could add up to....
     
  3. herler

    herler LawnSite Fanatic
    Posts: 5,144

    They are Echo machines, that's the problem.
     
  4. Oli

    Oli LawnSite Member
    Posts: 39

    Added 2-cycle oil to the cylinders of both units as described by Breezmister and checked the compression. Pressure increased to 105 psi on the trimmer, and 120 psi on the edger. Both units were around 90 psi before and after I installed new rings, and cleaned the carbon from the pistons, and cylinders. Does the increase in pressure indicate that these units are potential runners, or are the piston and cylinders too far gone? What would the compression be on a new unit? Thanks
     
  5. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,533

    At this point, with those numbers, I would put in new fuel lines and filters and see if you can get them to start. Now you will find out if the carbs are any good.....
     
  6. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,533

    Maybe, depends on if the carbs are FUBARed.
    As far as compression goes, Depending on the unit, be it a chain saw or a trimmer, 110+ is great.
    But, and this is my opinion, any thing over 90 that starts is good.
    One of our 026 Stihl chains saws only has 90 psi, it will start on the 1st or 2 nd pull, it is 12 years old.....
     
  7. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,142

    You are okay get a new carb kit and clean all carb ports openings. Be sure you know where the two carb adj needles are and adjust. When you had head off you should have cleaned all the internal ports.
     
  8. Oli

    Oli LawnSite Member
    Posts: 39

    Thanks for the input. My biggest concern was the cylinder compression. Yes, the cylinder ports were cleaned prior to re-assembly. I have had good luck in rebuilding these types of carbs and know where the adjustment needles are. These will be good back-up units when finished.
     
  9. dboyd351

    dboyd351 LawnSite Bronze Member
    Posts: 1,100

    Oli,
    Don't want to rain on your parade, but my experience is that anything under 100 psi is marginal on a 2 stroke. I'm not sure about your particular unit, but lots of 2 strokes, even older ones, have 140 psi or so. An older Husky 225 a guy recently gave has 140 psi. Poulan 3400 saws run well but are considered low compression saws - ones built in the 1980s usually run 120-130 psi, today, 30 years later.
    Putting oil in the cylinder is mostly a way of determining where the compression leakage is coming from, not fixing it. The compression increase when you added oil to the cylinder means you are losing compression past the rings.

    I've had chainsaws and trimmers with compression around 90 psi which would fire with a shot of fuel, but they were hard to get running well.

    I wish you luck, but wouldn't be surprised if you have trouble getting them running well. Please keep us posted on the results. I hope I'm wrong.
     
  10. Oli

    Oli LawnSite Member
    Posts: 39

    I am listening, and plan to move slowly. I think it is worth the cost of a carb kit to get one of the units running. If that works out well , I will swap the carb over to the other unit and see how it runs. I also plan to borrow another compression tester to verify my results and measure the cylinder to determine how much wear there actually is. I wish I could do this quickly and report back, but with Spring finally coming, my dance card is getting full. I expect I will learn something one way or other, and will report back. Thanks for the input.
     

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