Weed Trimmer, Runs in START, dies in RUN

Discussion in 'Tools' started by ozarkdan, Apr 24, 2013.

  1. Apr 24, 2013 #1

    ozarkdan

    ozarkdan

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    I have a Poulan PPB 150E weed trimmer that wouldn't start this season unless I shot fuel into the carb past the butterfly. Then it would only run for a few seconds. I replaced the fuel lines, filter, and carb. Now it starts and runs in the START position, but dies when I switch to RUN. Running in the START position, the RPM's tend to go up and down and white smoke will puff from the exhaust at times.

    Any suggestions?
    Could I have accidentally switched the lines to the carb?

    ozarkdan
     
  2. Apr 25, 2013 #2

    nealtw

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    Start position closes the chock so you get less air, so likely you have an air leak somewhere around the carb. Air leaking in where it shouldn't. Just a guess.
     
  3. Apr 25, 2013 #3

    Blue Jay

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    Ditto on the air leak, don't run it too long in this mode (don't ask me how I know) or you can ruin the engine...
     
  4. Apr 27, 2013 #4

    elbo

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    the engine is running way lean. It could be an air leak or a misadjusted carb. Check all the bolts on the carb including the attachment bolts for tightness. then squirt some gas around the parting surfaces and see if there is any change in the rpm, if there is, you've located the source of a air leak. It could be a torn gasket or "o" ring
    If there is no change in the rpm, then richen up the mixture until it runs without the choke being on. Once you get it running without the choke adjust the idle rpm and mixture until it runs evenly
     
  5. May 3, 2013 #5

    Daddytron

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    if you replaced the carburetor, odds are it's not adjusted correctly. if it has 2 adjustment screws (marked H and L) gently turn them in all the way and then out 1 1/2 turns each. warm the engine up for about a minute before going to full throttle, then adjust the "H" screw until it runs good. if it still runs poorly, then I would check for an air-leak. Usually an air leak will cause the engine to run way too fast. A leak in the bottom end will cause the engine to stall at idle.
     
  6. May 3, 2013 #6

    ozarkdan

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    Thanks very much for the feedback and ideas. Here's what I've done: 1. I applied high temp silicone grease around the gasket/O'ring and saw no difference in starting or running. This is a trick I learned working on cars. It's temp. but should've showed if there was a leak. 2. I held the choke in certain positions besides Full ON or OFF and found the engine would idle and run. This seems to indicate mixtures are not correctly set. Unfortunately, I do not have the right type of tool to adjust the carb screws, they're serrated.

    Dan

    Thank you all very much.
     
  7. May 3, 2013 #7

    nealtw

    nealtw

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    If the screws look like you need a 6 sided star, it's a torx scew screwdiver you need.
     
  8. May 4, 2013 #8

    Daddytron

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    no... Poulan used a splined screw for a while... more like a 4mm double square screw. I can't think if there's an alternative that a homeowner might have... Poulan was bought by "Electrolux Home Products" a while back. They also own "Husqvarna" if your local Husqvarna dealer is friendly enough They may loan you the right screwdriver
     
  9. May 5, 2013 #9

    ozarkdan

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    Kind of hard to describe exactly, but the heads of the adjustment screws had what looked like about 15-20 straight splines. I could put a piece of rubber tubing on them but they were too stiff to turn with the tubing.
     
  10. May 5, 2013 #10

    elbo

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    If I understand what you write, the splines are only to give you a grip on the adjustment screws. I would squirt some wd-40 around the screws and try to turn them with a pair of pliers, left then right a little at a time until they turn easily. I think they are just stuck or possibly over tightened. Be careful that the screw isn't bottomed out, so first turn it counter-clockwise, also, watch out for a plastic stop that will only allow you to make a small adjustment. these stops are removable, if you need to remove it See if you can post a photo of the adjustment
     
    Last edited: May 5, 2013
  11. May 7, 2013 #11

    Daddytron

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    The problem with the pliers is the screws are countersunk into the body of the carburetor. The screws go through a nylon plug moulded into the carb to keep them tight ant that makes it almost impossible to turn without the proper tool. I'll post a pic of the tool today.
     
  12. May 7, 2013 #12

    nealtw

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    Use a dremal to cut a slot in the top of the screw.
     
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  13. May 7, 2013 #13

    elbo

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    neal nailed it,
     
  14. May 8, 2013 #14

    Daddytron

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    Well, that's the easy way... This is what the screwdriver looks like

    DSC_0007-1.jpg
     
  15. May 8, 2013 #15

    nealtw

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    Looks like something you might turn with the rubber on a pencel or make something out of round stock with a three corner file.
     
  16. May 8, 2013 #16

    rockhound

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    Your spark plug is fouled, I would replace your spark plug. Then check your fuel tank for debreis
     
  17. May 15, 2013 #17

    ozarkdan

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    I am providing a photo of the adjustments on the carb. As you can see, they are spline'd and recessed. Because they are recessed, cutting slots into the ends is pretty difficult unless I find a way to remove them first.

    PoulanCarb01.jpg
     
  18. May 15, 2013 #18

    nealtw

    nealtw

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    Boy, you don't need to many reasons not to buy this product. This doesn't look the same as Daddytron's sample. What part do you think truns
     
  19. May 15, 2013 #19

    nealtw

    nealtw

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  20. May 15, 2013 #20

    ozarkdan

    ozarkdan

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    What I found out is that Electrolux bought Poulan some time ago and they were the ones responsible for changes to a number of products, including the weed trimmers. Apparently they couldn't make up their minds on the carbs because, as I understand it, there are a number of versions that were used until recently.

    Anyway, the black center parts in the photo are the adjustment screws. Since I bought a replacement carb, I have decided to remove the screws from the old one, slot them and then replace the ones in the new carb with ones I can adjust.

    I had taken the weed trimmer to Northern Tool which is an authorized repair place and had the mechanic look at the trimmer. After I explained what it was doing and what I did, replaced the carb, he was able to get it running right by making some carb adjustments. Now it starts and runs as it should. So, if I remove the current screws and keep track of the number of turns, I should be able to put my (now slotted) screws in at the same settings and have a running trimmer again.

    Thanks to all of you that contributed to this Thread and provided helpful input towards resolving this issue. I hope that the info shared here will be of help to others as well.

    Thanks guys,
    ozarkdan
     
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