Chainsaw going through plugs?

Discussion in 'Mechanic and Repair' started by D Felix, Jan 11, 2005.

  1. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    I've got a Poulan 2025 chainsaw (I KNOW it's a POS, but it's what I've got at the moment) that I've had to put 2 spark plugs in in less than an hours worth of run time....

    The first replacement was a CJ6, it replaced a CJ8Y. The 6 was what I could find at the time.

    The next replacement was a CJ8, it replaced the 6.... It's now running fine. But, I haven't run it much with the new 8, just enough to get it started and adjust the idle screw a bit. Haven't used it since- it's been raining.

    The reason I put in the 6, is because with the 8Y, it wouldn't start at all, wouldn't even act like it wanted to. I had spark, I tested that. Someone told me the plugs could break down under compression, so I changed it out and it ran fine with the 6.

    Then it crapped out on me with the 6. I realize they are different heat ranges, but to just die suddenly like that, is that normal?

    I've also opened up the muffler a bit, in an attempt to gain some power- I think I've got a 1/2" and 3/8" holes drilled in the muffler in addition to what was stock. Yes, I did re-tune the carb when I did that (as best as I could by ear, at least). I opened up the muffler last year, and I had several hours of operation with the original CJ8Y plug after that.

    Any thoughts (other than to get a different saw)?

    I'm thinking I need to start watching eBay for a new saw, but the budget just doesn't allow for much right now..........

    Thanks in advace!


    Dan
     
  2. Gautreaux's LNG

    Gautreaux's LNG LawnSite Senior Member
    Posts: 379

    Get a husqvarna Dan, Later
     
  3. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    What part of that don't you understand?

    If I had my way, I'd get a Stihl, Husky or Jonsred. BUT, the checkbook won't allow it.


    Dan
     
  4. Mikes Machines

    Mikes Machines LawnSite Member
    Posts: 112

    This may sound like a stupid question but not being able to see what is happening makes it difficult to lend advice. What was wrong with the plug?
    What did they look like when you took them out?
     
  5. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,454

    Are you leaning the carb to get more rpm's or trying to run it fatter for more power?

    What fuel/oil ratio are you using?
     
  6. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    Niether plug looked abnormal. Both were the normal tannish color. The only reason I changed out the CJ8Y was because of the comment that was made to me about the electrode breaking down under compression. The 8Y had been in it for a while, I don't remember if it was the original plug or whether I had changed it out somewhere along the line.... Again, nothing looked wrong with either plug. The damn saw just WOULD NOT start with them in there. Kinda like a little kid, you try to get them to eat something they don't like, and try as you might, they just won't eat it. That's the way the saw was, I tried everything, but just couldn't get it started.

    I don't think the carb is too lean. I re-adjusted the carb after I drilled the holes in the muffler. At least as best as I could by ear. The saw isn't worth taking to a shop to get the carb tuned, with a shop minimum of ~$25.

    I'm using the recommended 40:1 ratio on the gas. And the gas was just mixed ~2 weeks ago, so it's not old.

    I don't remember what happened when it wouldn't start with the 8Y in it, but this last time I was using it to cut wood into firewood sized pieces. I was cutting down through the top (but not all the way because of the dirt), and about 5-6 pieces later finally was able to cut all the way through. In the process of trying to flip those 5-6 pieces over, the saw died and I couldn't get it re-started. Brought it home, changed out the CJ6 for the CJ8, and it fired right up.... I think it may have been a similiar situation the first time- it just died and I couldn't get it started again....


    Dan
     
  7. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,454

    Fatten up the mixture until the rpms start to drop and the saw should have the best power and won't fry plugs.
     
  8. Mikes Machines

    Mikes Machines LawnSite Member
    Posts: 112

    Oldtimer has a good point, if you adjust it by ear it may be to lean, adjust it for max rpm then richen it up some. The correct way to do this is with a tach and a spec from the manufacturer. If it is to lean it may be heating up the plugs enough to damage them.
     
  9. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    Refresh my memory, is richer in or out on the screw?
     
  10. Mikes Machines

    Mikes Machines LawnSite Member
    Posts: 112

    Almost all engines are richer when you turn the screw out. There are a few engines that work the opposite because it is an air bleed type of system but I have never seen one of these on a saw.
     

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