Anne_A
ArboristSite Lurker
Hello all, I'm new here and am in need of some help. Recently I acquired an "older" Poulan 335 Pro (20inch bar). It has been very stubborn about starting and when it actually was starting it would lose power at full throttle, stall and die. It was also idling very unevenly but that was somewhat fixed by running carb cleaner and adjusting the L mixture screw. I was able to get it to run slightly better at high speed by adjusting the H screw on the carb but the problem still persisted and seemed to get worse the more I ran it. I assumed this was a carburetor issue based on the way it was bogging down and stalling so I decided to rebuild the carb and replace the fuel lines while I had the saw apart. The fuel lines were very brittle and starting to crack so they were definitely in need of replacing. I also changed out the spark plug since the plug it came with was dirty and beginning to foul.
Since rebuilding and cleaning the carburetor the saw has been even more stubborn about starting and will not run for more than about 15 seconds if it starts at all. The carb is a walbro HDA-49 and was rebuilt using the kit specifically for the HDA carbs (part number K22HDA).
I have now cleaned the air filter, rebuilt/cleaned the carb, cleaned the exhaust screen located in the muffler, replaced the fuel lines, and replaced the spark plug but I am still having trouble.
After rebuilding the carb I set both the L and H adjustment screws to 2 full turns (360 degrees) out from all the way in. I've made adjustments to both screws in 1/4 turn increments and have seen little affect on the saws performance. The saw seems to be firing a little better when the H adjustment is set close to 3 full turns out and the L screw is set to a little less than 2 turns out. The idle adjustment screw doesn't seem to help keep the engine running with adjustments in either direction.
I have not checked compression with an actual gauge but have tried to plug the spark plug hole while pulling the starter cord and am unable to keep it sealed with my thumb when I pull the starter cord at a normal starting rate. If I pull extremely slowly I can mostly keep the hole sealed off. I know this doesn't give us any real numbers to go off of but I believe it does tell me that compression has not been lost completely.
I have checked that the piston does in fact move when the starter cord is pulled. When the spark plug is removed it's very easy to see the piston moving up and down when the cord is pulled.
At this point I'm not sure what else to do besides start checking the actual engine (cylinder, piston, crankcase, etc.). However from my limited experience with other 2 stroke engines this seems more like an issue with the carburetor than anything else.
Does anyone have any suggestions on what else I could try? Any help would be appreciated.
Oh and I did change out the gas when I first got it. It's running regular unleaded gas with 2-cycle oil mixed at a 40:1 ratio.
Since rebuilding and cleaning the carburetor the saw has been even more stubborn about starting and will not run for more than about 15 seconds if it starts at all. The carb is a walbro HDA-49 and was rebuilt using the kit specifically for the HDA carbs (part number K22HDA).
I have now cleaned the air filter, rebuilt/cleaned the carb, cleaned the exhaust screen located in the muffler, replaced the fuel lines, and replaced the spark plug but I am still having trouble.
After rebuilding the carb I set both the L and H adjustment screws to 2 full turns (360 degrees) out from all the way in. I've made adjustments to both screws in 1/4 turn increments and have seen little affect on the saws performance. The saw seems to be firing a little better when the H adjustment is set close to 3 full turns out and the L screw is set to a little less than 2 turns out. The idle adjustment screw doesn't seem to help keep the engine running with adjustments in either direction.
I have not checked compression with an actual gauge but have tried to plug the spark plug hole while pulling the starter cord and am unable to keep it sealed with my thumb when I pull the starter cord at a normal starting rate. If I pull extremely slowly I can mostly keep the hole sealed off. I know this doesn't give us any real numbers to go off of but I believe it does tell me that compression has not been lost completely.
I have checked that the piston does in fact move when the starter cord is pulled. When the spark plug is removed it's very easy to see the piston moving up and down when the cord is pulled.
At this point I'm not sure what else to do besides start checking the actual engine (cylinder, piston, crankcase, etc.). However from my limited experience with other 2 stroke engines this seems more like an issue with the carburetor than anything else.
Does anyone have any suggestions on what else I could try? Any help would be appreciated.
Oh and I did change out the gas when I first got it. It's running regular unleaded gas with 2-cycle oil mixed at a 40:1 ratio.
