Service & Maintenance Question
I have a Poulan Pro 131, 31cc heavy duty, straight shaft,...escalated
Service & Maintenance Question posted June 18, 2014 by Dan Broomhead
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Question:
I have a Poulan Pro 131, 31cc heavy duty, straight shaft, gas trimmer that will start just fine when cold, but if stopped for any reason, will not restart until the engine is cold again, usually an hour later. Why?
Details:
I am 34 and not very familiar with engine repair of any kind. However, I am very mechanically inclined and can pretty much disassemble, repair, and correctly reassemble anything I put my mind to.
Now for the problem. I have recently purchased a Poulan Pro 131 31cc heavy duty straight shaft trimmer from Goodwill for the very high price of $12.99, I figured at that price why not take a chance, what could it hurt. After getting it home and looking at it I saw that the fuel lines were done for. I replaced them with a kit from Lowes. The trimmer started right up. I stopped it and restarted it right away with no problems. I stopped it again and let it sit for a few minutes while I cleaned up the head. Tried to restart it...no go. I double checked to make sure the fuel lines weren't kinked and they were fine. I delved further into the engine, foreign territory. I paid very close attention to how things went and snapped pictures along the way.The carb looked clean but I took it apart to clean it anyway. It was spotless in every way, the diaphragms even looked new and flexed just fine. I delved further, the spark plug had a little buildup on it but sparked fine. The cam and piston moved freely and the piston was clean. The cylinder was spotless, no scratches to be seen, though I didn't disassemble any further on that part. The muffler was clean with no buildup whatsoever. There is no spark arrestor screen over the spark plug, but there is a screen in the muffler that I assume acted in the same way, it had no buildup either. Pretty much everything looked practically new. I reassembled everything correctly according to my memory and the pictures I took. The engine will start right up when it is cold, however, if I stop it for any reason, it will NOT restart until the engine is cold again, usually an hour later. I have fiddled with the two screws on the carb while it was running in order to get the idle smooth and the acceleration (right word?) smooth. Now, the fuel/oil mix is just barely oil rich, I mixed 4 ounces of oil into 1.25 gallons of new, clean gas, trying for a 40:1 mix like the trimmer stated.
Now, like I said, the engine starts fine when cold, but will not restart when hot. I only have 30 bucks invested in this thing, but I really want to get it running. I can't afford a new trimmer and I hate my dad's battery powered Black and Decker. With all of the above in consideration, what else can I do, or needs to be done, to get this thing running?
Now for the problem. I have recently purchased a Poulan Pro 131 31cc heavy duty straight shaft trimmer from Goodwill for the very high price of $12.99, I figured at that price why not take a chance, what could it hurt. After getting it home and looking at it I saw that the fuel lines were done for. I replaced them with a kit from Lowes. The trimmer started right up. I stopped it and restarted it right away with no problems. I stopped it again and let it sit for a few minutes while I cleaned up the head. Tried to restart it...no go. I double checked to make sure the fuel lines weren't kinked and they were fine. I delved further into the engine, foreign territory. I paid very close attention to how things went and snapped pictures along the way.The carb looked clean but I took it apart to clean it anyway. It was spotless in every way, the diaphragms even looked new and flexed just fine. I delved further, the spark plug had a little buildup on it but sparked fine. The cam and piston moved freely and the piston was clean. The cylinder was spotless, no scratches to be seen, though I didn't disassemble any further on that part. The muffler was clean with no buildup whatsoever. There is no spark arrestor screen over the spark plug, but there is a screen in the muffler that I assume acted in the same way, it had no buildup either. Pretty much everything looked practically new. I reassembled everything correctly according to my memory and the pictures I took. The engine will start right up when it is cold, however, if I stop it for any reason, it will NOT restart until the engine is cold again, usually an hour later. I have fiddled with the two screws on the carb while it was running in order to get the idle smooth and the acceleration (right word?) smooth. Now, the fuel/oil mix is just barely oil rich, I mixed 4 ounces of oil into 1.25 gallons of new, clean gas, trying for a 40:1 mix like the trimmer stated.
Now, like I said, the engine starts fine when cold, but will not restart when hot. I only have 30 bucks invested in this thing, but I really want to get it running. I can't afford a new trimmer and I hate my dad's battery powered Black and Decker. With all of the above in consideration, what else can I do, or needs to be done, to get this thing running?
