Need help with Poulan 235 chainsaw?

Discussion in 'Shop Talk' started by unioncreek, Dec 19, 2005.

  1. unioncreek

    unioncreek Well-Known Member Supporter

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    I have a Poulan Pro 235 chainsaw that is about 13 years old, it has run great until this fall. I was putting in fence and trimming trees at the same time and it started to run funny about the time I was done using it.

    I needed it the other day and it would start and run, but would not idle down worth a darn. I adjusted it according to specs and it still did it. I put it aside until last week and now it will not run at all unless I squirt gas in the carb. The hose and filter to the tank are not plugged. I'm thinking of taking the carb apart, but would like a littl input on what to look for and any hints that might help solve the problem.

    Just never worked on one before and am hesistant to just pull it apart.

    Thanks,
    Bobg
     
  2. michiganfarmer

    michiganfarmer Max Supporter

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    chain saws pump fuel by using the crank case vaccume. My stihl did that one time, and I didnt know how fix it. I took it to a Stihl repair center. They said a gasket in the crank case was bad wich wouldnt allow it to make vaccume. When I got it back it ran fine
     

  3. Cabin Fever

    Cabin Fever Life NRA Member since 1976 Supporter

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    If the air cleaner is clean, and the adjustment screws for idle, air/fuel mix and high speed are to specs, and it still runs rough, I will clean the carb. I'll take the carb off and spray it with carb cleaner. I'll take the bowl off to get at the insides and spray it there too. I'll spray into all the orifices and jets, too. They I put it back together and back on the implement. 9 times out of ten it will run great after that.

    The other thing I'd check on your saw is the spark arrestor. On my saw, the spark arrestor is a little piece of window screen over the outlet on the muffler. The screen may be plugged with carbon which causes a back pressure which causes a rough running saw. Take the screen off and start the saw....see if it doens;t run better. If it does, clean the screen or remount it over a currently clean spot.
     
  4. agmantoo

    agmantoo agmantoo Supporter

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    Get an rebuild kit for the carb off the internet. It will come in the mail and it is cheap. A portion of one of the gaskets is the fuel pump and when the gasket gets old or gummy it will cease to flutter/pump. Clean the carb thoroughly while you have it apart. There are some very small orifices so make certain they are not blocked. The information for the particular carb you have is molded into the carb housing.
     
  5. BigBoy

    BigBoy No attitude here...

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    My Stihl did the exact same thing to me. I took the carb apart and cleaned it and replaced the fuel hose and filter. The air filter looked fine and had few hours on it. I finally took it in and all they did was replace the ($27!) air filter. Works every time now.
     
  6. moopups

    moopups In Remembrance

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    A two stroke engine's fuel comes in through the scavanger ports, the holes in the side of the cylinder wall from the pressureized crankcase. That is why the oil and gas is mixed, so the crankshaft can be lubricated. If the seals at each end of the crankshaft have failed, exspected at 13 years of age, it will not crank or run right . Usually it will hit a few times and die, repeatedily. Replacement of the seals is the only cure for this condition. This requires spliting the cases and is not a job for an inexperienced person.
     
  7. Richard6br

    Richard6br Well-Known Member

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    Change the sparkplug. My Poulan is 20 yrs old and started acting up real bad. Real hard to start and wouldn't idle at all once it was started. Put in a new sparkplug and it runs like new.
     
  8. HUBERT

    HUBERT Well-Known Member

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    Check spark arresstor screen on muffler is not plugged up from carbon.If it is clean or replace .
     
  9. michiganfarmer

    michiganfarmer Max Supporter

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    after he gets through with all of this advice he will have a new saw, lol
     
  10. horselogger

    horselogger Well-Known Member

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    and the sad fact is that a new saw would have been cheaper and better!!!
     
  11. raymilosh

    raymilosh Well-Known Member

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    I have owned and tinkered with stihls, poulans, echos, jonsereds and homelites and every one has a very small very fine screened filter inside the carburator. Usually, the screen is shaped like a shallow open topped cylinder about the diameter of a pencil eraser. A screen is basically stuffed into the hole and it eventually fills with very fine particles (so fine that they passed through the filter in the tank). to find it, follow the path of the fuel from where it comes into the carburator. It passes through this filter before going anywhere else. the filter mesh is so fine that it is hard to recognize it for what it is. I suggest poking around gently with a toothpick until you find that you have discovered a shallow bowl full of mush. rinse it out, then pick the filter out with the tip of a knife and rinse it off.
    the symptoms of the high idle point to a clogged filter, by the way. the engine is starving for fuel, so the mixture is lean which causes a higher idle. the same thing happens when the saw is running out of gas.... for the last few seconds before the engine stalls, the idle goes way up. I have always assumed it is because the mixture is getting lean.

    Just getting to the carburator the first time is usually the hardest part. they can be really buried in there...but keep at it. On my poulan, i had to withdraw the engine from the body of the saw to get to the carb.