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Poulan 2050 fuel lines


rickman235's Avatar
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04-14-09, 11:54 AM   #1  
Poulan 2050 fuel lines

Poulan 2050 chainsaw. Fuel line routing? Replaced all fuel lines. Primer bulb is marked tank and carb side. Tank side is for larger line and runs into tank and fuel filter. Carb side is smaller diameter line and runs to carb but which fitting? Remaining carb nipple with small line runs to tank vent and sticks about 1 inch into tank top. Pushing on primer bulb PUSHES air OUT of fuel filter and sucks from carb side of bulb. Pulled out primer bulb and verified action separately. Definitely pulls from carb side and pushes into tank side which makes no sense to me at all. Going backwards like that would require source of gas to be from "vent" line in tank which isn't low enough into tank and would not be filtered. Can't believe primer bulb is suddenly working backwards. Hope you can help. Thanks. Rick

 
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cheese's Avatar
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04-14-09, 10:33 PM   #2  
You've got it hooked up wrong. The tank side of the primer goes to the vent. The carb side of the primer goes to the carb return, and the filtered line goes to the carb inlet.


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rickman235's Avatar
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04-16-09, 12:33 PM   #3  
Thanks Cheese. Played with the two carb fittings until I had good flow through entire circuit working primer. Still not even a putter though. Good spark at plug. Tried fuel in weed whacker-fine. Compression 45 psi on 1st pull and 60+ on 2nd. New piston ring. Walls looked good. Tried fuel right into carb throat. Compression could be bleeding off as fast as developed though. Guage won't check for that. Don't know if I should invest more time and money but hate to stop now.

Rick

 
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04-16-09, 01:00 PM   #4  
60 lbs isn't enough, you need over 90 to start it. Did you hone the cylinder? If you did were you taking out scoring?

If so you probably have a bad cylinder = unusable.

 
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04-16-09, 01:43 PM   #5  
Did not hone the cylinder walls. Saw ran fine last year. Fuel lines were rotted and I broke the piston ring during re-assembly. Thinking case leak. Re-used crankcase seals on bottom/sides hoping I could get away with it. With low compression now, I'm guessing I didn't.

 
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04-16-09, 01:51 PM   #6  
Put a little two stroke oil in the cylinder (about an ounce), til the saw around to distribute the oil into the piston gap in the cylinder and recheck the compression. See what you get.

 
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04-17-09, 06:50 AM   #7  
Grabbed some gear oil and did that. PSI was much improved for a while but the continual cranking thereafter brought it back down again. Even with the higher compression, the introduction of fuel mixture into the carb throat still gave no results. What do make of that? Since I re-used the seals and gaskets, don't you think there's a high chance that the case is leaking compression?
Thanks.

 
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04-17-09, 06:57 AM   #8  
I believe the compression loss is at the ring/cylinder walls. The crank seals have an effect on everything factored into the running of the engine, but the rings sealing in the cylinder would be more than the crank seals in the compression.

If you haven't had damage to the piston or the cylinder walls prior to the dismantling of the engine, I would try honing the cylinder with a fine stone and see if that doesn't get you a seal at the rings.

The adding of oil in the cylinder is a test to determine where the compression loss is occurring. It isn't to start the engine or anything of that nature. When you added the oil and the compression came up that tells you the leakage is at the ring/cylinder.

 
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04-18-09, 06:25 AM   #9  
Strange that the saw ran so well before all this. Well, it looks like it's coming apart again for a better look at the cylinder walls and possible honing. But since my test was with a heavy gear oil and not the thinner 2 cycle oil suggested, what might it point to if I re-run the test with the thinner oil and the compression is still not good?

 
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04-18-09, 11:15 AM   #10  
Nothing really. The reason the thinner 2 stroke was suggested was a residue issue. The two stroke oil would have blended burned itself out more readily. The gear oil pointed the same direction and would have served the same purpose.

Likely as not (with some room for error), the seating of the new ring is the issue.

 
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06-03-09, 01:37 PM   #11  
What was the outcome of your difficulty with the primer bulb and routing the fuel lines on your poulan 2050? I am having the same exact problem you have described. The saw stopped working in the field and when I started checking it out the primer bulb appears to be working backwards. Please share your discoveries, thanks,

 
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