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Husqvarna 128LD Edger Races/Runs only on Half Choke.

Discussion in 'Hand Held Equipment and Tools' started by chainsawdave, Dec 29, 2019.

  1. chainsawdave

    chainsawdave ArboristSite Lurker

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    I was given a 128LD with LE720 Edger attatachment. Previous owner was frustrated with it but I don't know how/if they trie to fix it--i.e. no Repair History given to me.

    First thing I did was to dump the fuel tank into a glass jar (yep, small amount of water was found) then refill the fuel tank to about 1/2 inch deep with fresh 50/1 non-ethanol fuel (same fuel mix/jug that runs fine in my Husqvarna 223L Trimmer--i.e. known good fuel). Following prescribed starting procedure the engine starts fine on Full then Half Choke, although it races/HighRPM on Half Choke. Moving to Choke Off the engine dies, throttle cannot keep it running. The edger blade rotates continuously during all this.

    Before I dig deeper into this problem (i.e. replace fuel lines, disassemble carburator, etc) any hints what I should look for? My experience with outboards/mowers/chainsaws/trimmers/blowers leads me to a hunch that engine is starved for fuel i.e. leaning out. Therefore either a constricted fuel line/filter or something else in the carb. I have done a little work but not a lot with Walbro carbs.

    Also, what size spark plug wrench do I need? My "socket set" 5/8inch doesn't fit, and the cheapo stamped metal 3/4 inch wrench slips around the spark plug (do I need to buy a socket set type 3/4inch?

    Thanks in advance for any tips.
     
  2. Manic84

    Manic84 ArboristSite Member

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    What series/variant of walbro is it? let us know.

    Follow though with your hunch, you can try adjusting (if you can) the L & H needle screws out 1/4 to 1/2 a turn each and adjust the idle speed screw as well.

    If that doesn't affect it, the fuel strainer screen and innards of the carb might be gummed/plugged up and worth looking at, try to find an OEM rebuild kit and clean it out.

    The spark plug wouldn't happen to be a champion RCJ8Y would it? they are usually 3/4-19mm.

    It wouldn't hurt to look into a socket, not only for convenience and leverage but reliability too.
     
  3. chainsawdave

    chainsawdave ArboristSite Lurker

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    I was wrong, it is not a Walbro, it is marked " Zama China W40A 502A 118". probably a Walbro knock-off? Yes the spark plug is RCJ8Y, I will buy a good quality 3/4 inch wrench.
    I did some diagnosis today. I noticed that the primer bulb fills up around 3/4 to 7/8 when pumped 10times, but it does not fill fully. Both the Pressure Line and the Suction (one with filter on end) are a "slip fit" not a tight/compression fit to the fuel tank. It is possible that a previous owner drilled out the holes in the fuel tank because they didn't know the "guide wire/tapered end of fuel line" trick to pulling a tight-fitting fuel line through the holes in fuel tank. I keep 3 sizes of fuel line on-hand and all of them are too small on Outside Diameter to make a proper tight fit in the holes. Other thing I noticed is that the Intake Gasket that lays on Manifold side of Carb is torn/deteriorated. This would definitely cause a leak. I am unsure what p/n to order. The Engine Parts Diagaram on Jackssmallengine looks like #5 p/n 545008086 (picture doesn't look right) or #7 p/n 545008084 (picture looks right but has "extra parts" I don't need) or #64 p/n 545008084 (same extra parts). Which is correct p/n? I am also considering fabricating a new gasket from flat gasket stock that I already have on-hand.

    BTW I have had excellent results soaking carburetors in 70% or higher Isopropyl alcohol to remove residues/"goop" from ethanol gas (I run only non-ethanol in all my small engines except some 4 stroke lawnmowers/lawntractors). I might soak this carburetor too, of course that would be next step if remedying fuel lines and Intake Gasket doesn't solve the problem.

    Any additional input is welcome.
     
  4. Manic84

    Manic84 ArboristSite Member

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    The fuel lines should be 3/16 OD 3/32 ID, If someone drilled out the holes, you might have to go up a size but that has it's own issues. Maybe the lines might have just shrunk over time, what do the lines look like, are they yellowed/aged looking?

    There should usually be a little air bubble in the purge bulb so it only filling up 3/4 - 7/8 seems normal.

    The carburetor is likely a Zama C1Q-W40A it should be embossed (C1Q) on the throttle linkage/adjusting screws side, it might be hard to see but it's there (please confirm). If so it's kits are RB-47 (needle included) & GND-18 (gaskets only).

    Then the part numbers... oh boy... it might be some oversight on the site you mentioned, but the list/P/N's are slightly different than the OEM one. But i think it's this one:

    #5 545008086 #5 should have the carburetor gasket and (should) have the foam gasket and the rubber seal that's behind the insulator block.

    I would put "Husqvarna 545008086" into ebay and you'll get a better picture (maybe better price?)


    Hope that this helps you, Good Luck:)
     
  5. chainsawdave

    chainsawdave ArboristSite Lurker

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    Manic84, thanks a lot for your input.

    I will try to use 3/16 OD 3/32ID fuel line and not go up in size if at all possible. The old lines are very yellowed/aged--I am surprised they are not cracked (I tested by plugging 1 end and blowing into the other end). Yes the old lines appear to have shrunken.

    Glad to hear some air in the purge bulb is normal.

    Yes the carb is embossed (laser marked?)on the throttle linkage/adjusting screws side--not hard to see at all. It says " W40A " with "502A" directly under that on a 2nd line.

    I have ordered a Kit on Amazon, I am unsure what all the kit contains--As a minimum from the photos on Amazon it appears the kit contains the necessary gaskets 545008086 but also the photo on Amazon shows carburetor, purge bulbs, fuel lines, etc for only $6.99 including Free Shipping! I find it hard to believe all these items (including Shipping) for only $6.99 but let's wait and see--parts should arrive around Tuesday if I remember correctly. I will update next week.

    Thanks again,

    Dave
     
  6. milkman

    milkman Addicted to ArboristSite

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    I have a 128LD and broke the fragile choke lever on the carb, I ordered a chinese carb, don't remember the price but was really cheap. I was skeptical, but it has been running without a hiccup.
     
  7. chainsawdave

    chainsawdave ArboristSite Lurker

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    I fixed/replaced the 2 loose fuel lines and the bad Intake Manifold gasket. I also soaked the carb in 70 percent isopropanol. No change, It still runs only when on Half Choke.

    I think a new carb is next step because one brass tube going into the carb (the tube on the Purge Bulb half of the carb) seems blocked. I can't blow or suck air through this tube. With a fine wire I was unable to dislodge anything from this tube/side. The other tube/side is OK.

    Is my diagnosis (new carb needed) correct? New carb is cheap (only $10) but my wife is going to be really ticked if I place another order for parts and it doesn't make a dent in my backlog of tinkering projects (current backlog = 7 small outboards, a gas blower and this Edger. Although I do have ONE outboard that is working lol).

    Thanks,

    Dave
     
  8. chainsawdave

    chainsawdave ArboristSite Lurker

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    Attached photo shows the tube that seems to be clogged.
     

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  9. Okie294life

    Okie294life Small engine jackwagen.

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    Have you tried taking some carby cleaner and a brush or wire to clean out the jets, the little wire screen and all the passages? As long as the diaphragms are still good in the carb....and you put it back together right it should be a fix, provided you can get a fuel line I thats not sucking air. Have you checked to make sure both jets are at default? That’s usually the first thing I do when something doesn’t run first thing people do is start dickering with the carb jets.
     
  10. Manic84

    Manic84 ArboristSite Member

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    If I'm not mistaken, that should be the purge return outlet, it should be a one-way flow, if you're unsure, a quick way to test it is to put a fuel line on it and the other end of the line in some fuel and press the bulb. If air (bubbles) appear it's the return outlet.

    Just out of curiosity, what did the kit that you ordered have?
     
  11. chainsawdave

    chainsawdave ArboristSite Lurker

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    I cleaned out the wire screen it was maybe 10-20 percent clogged. I soaked the carb in isopropanol and blew out what passages were accessible. Diaphram looks good. What are the jet default settings? Also what is the trick for turning the jets without a special tool? IF I recall correctly, a wire crimp connector (red, blue or yellow?) works pretty good. BTW I checked Fuel Cap, Exhaust Port and Spark Arrestor. All good.

    Checking the Purge Bulb--when pressed fuel came out of the bulb (bulb was initially full of fuel) but it doesn't seem to blow bubbles when open end is in a small jar of fuel. I will try this test again tomorrow (I am changed out of my shop clothes for the day, wife doesn't like me sitting around the house in evening smelling like gas!). If the test has good results then I have to conclude root cause is either 1) an internal passage that I can't reach is blocked or 2) jet settings are wrong.

    The kit contained 2 different sized fuel lines, maybe 18inches each, 2 fuel filters, 2 spark plugs, 2 purge bulbs, Intake Gasket and Gasket that goes on near side of carb toward Air Filter. I really bought it for the intake gasket because mine was mangled, so other items were a bonus.

    Thanks for ongoing advice.
     
  12. Manic84

    Manic84 ArboristSite Member

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    Replace the fuel filter (if you haven't already), if the bulb looks aged or wrinkled replace it too.

    When you pressed the bulb with the line connected on the return outlet and the other half of the line in the fuel, it sounds like it's clearing out the fuel in the carb and bulb like it should, if you press the bulb and fuel is coming out of that line/outlet it's probably fine.

    When the bulb is pressed, the fuel inlet/line draws fuel from the tank (filtered end), while the return outlet/line (usually nothing on the end) puts air or excess fuel back into the tank. Without the line from the tank connected, no fuel is coming in to replace what was returned, just air, draining the amount of fuel in the bulb. If you keep pressing the bulb you'll just push the fuel left in the carb/bulb back into the tank, with no fuel left in the carb/bulb and with no fuel coming in and you press the bulb, you'll see/hear, air/bubbles appear on the end of the return line.

    Mixture Screws
    As a base setting zama recommends one (1) turn out each for the mixture screws, but I usually give them one and a half (1 1/2). But count how many turns they already have before you try to adjust them.

    If you don't have the adjusting tool, you could use a electrical connector (find one that fits the screw) or use a blue bic pen (pull the ink cartridge out). Although it's probably a better investment to get the tools for future projects in the long run.
     
  13. chainsawdave

    chainsawdave ArboristSite Lurker

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    I had replaced the fuel filter already when I replaced the fuel lines. Just now I replaced the Primer Bulb although the old bulb seems perfectly good. I also adjusted using an electrical connector (Butt Splice Crimp Connector)--the blue 14/16 Gauge connecter was the best fit. However it wasn't a perfect fit--I was unable to count the turns exactly because the connecter slips a bit. Good news is the engine seems to run a bit better, but not good enough yet--so maybe this has been a mixture screws adjustment problem all along (unlikely problem was/is the primer bulb. Shame on me for changing 2 possible root causes at one time). I couldn't find a splined carb adjustment tool locally, so I have ordered one on-line. It could be a couple weeks until tool gets here. I will update after I use the tool to make proper mixture settings. Thanks.
     

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