Hello all. I was trying to get an old poulan saw I have to run. I poured gas down the carb and the saw will run but dies when the gas I poured in it is exausted. Then I started having the same problem with my old homelite, which was running good before hand. The Poulan saw, I took the carb apart and it was clean as a whistle. I thought maybe it was all varnished up or the screen was dirty, not the case. It is a Tolliston carb. My question is: What is the most common thing that causes this problem? What can I try next. Thanks
Two saws, same problem!!
- Thread starter gr8mac
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No carb kit yet. I have only had the poulan carb apart so far. As I said in my original post it looked really good, as did the diaphram. I know that looks can be decieving though. I am new to working on my own saws. So I don't know what you mean by pulse line. Is that the line in the tank?
Tony Snyder
Addicted to ArboristSite
Fill your gas tank, take the fuel line loose at the carb, probably with a pair of needle nose, tip the and see if you get a stream to run from the fuel line. If you do not, and get just a slow drip, your filter gummed up. They can be decieving, look good and be plugged.
Then I guess the next thing I would do is to try to determine if you have pumping pulse to the carb.
Did you blow spray carb cleaner through the carb passage or check to see if they were clear with a tag wire?
It sounds like it is not running long enough to poit to a blocked tank vent.
Then I guess the next thing I would do is to try to determine if you have pumping pulse to the carb.
Did you blow spray carb cleaner through the carb passage or check to see if they were clear with a tag wire?
It sounds like it is not running long enough to poit to a blocked tank vent.
No I haven't run any carb cleaner through it yet. I will try what you suggested about the filter. How do I check to see if there is pulse to the carbs? Forgive my ignorance but I don't know what you mean by a tag wire either. I am a newbie, green as green can get. One good thing is that I am mechanically inclined. lol Just never worked on saws and I am trying to learn.
I just went and filled the tank of that old poulan to the gills. Removed the fuel line from the carb like you suggested. The I tipped the saw upside down and didn't even get a drip out of the line. Does this mean my fuel filter in the tank is clogged or do I have a siphon problem????
TonyM
ArboristSite Guru
The pulse line connects the crankcase to the carb, specifically to the backside of the diaphragm. The pulsing action from the pressure changes in the crankcase are what move the diaphragm to pump the fuel. If the pulse line has a leak, or is collapsed or pinched, you will essentially have no fuel pump.
Is the pulse line external or internal. The only line connected to this old carb is the fuel line that goes into the bottom. The Poulan is a model 31 with a Tollitson HL 83A Carb. The homelite has the Tillotson HL-119A Carb.
sedanman
Just cut the piano!!
If there is only one lone to the carb then the pulse is a tiny port in the carb gasket. take the carb off, put a small dab of grease or vaseline over the pulse port and pull the rope. You should see the grease displaced. The pulse post can get plugged up internally.
