chilliwillee
New member
I am working on a Poulan Predator 42cc. It all began when it quit while being used and then wouldn't start. The plug smelled of fuel, so I replaced it and it immediately fired but wouldn't stay running. If you started it with the choke partially on, it would stay running as long as you didn't touch the throttle.
I cleaned the carb, made sure all of the orifices were clear, and reassembled. Then it would stay running with the choke off as long as it is on high idle and you don't touch the throttle.
I checked the spark arrester, and it is clear.
I bought a carb online and installed it. Now it would only start if you hold the throttle wide open. It wouldn't come to full RPM and was blowing fuel back through the carb. I can ease off on the throttle to about 90% throttle, but then it quits. I tried adjusting, but nothing helped, so I went back to the original carb.
If I very slowly pull the throttle, it will take a bit more, maybe 10% more, than the high idle, but then quits. The same with easing off on the throttle, it quits almost immediately. As long as it is on high idle, it will run all day.
Adjusting the mixture screws does have an effect, with the saw slowing down as you turn a screw in or out, with a sweet spot at about 1.5 - 2 turns.
I haven't done a compression test, (can't find my gauge) but compression seems good going by the tension on the pull cord.
One other point; this carb has the extra butterfly on the top to allow extra air. Could it be getting too much air? Why have they added that butterfly?
I cleaned the carb, made sure all of the orifices were clear, and reassembled. Then it would stay running with the choke off as long as it is on high idle and you don't touch the throttle.
I checked the spark arrester, and it is clear.
I bought a carb online and installed it. Now it would only start if you hold the throttle wide open. It wouldn't come to full RPM and was blowing fuel back through the carb. I can ease off on the throttle to about 90% throttle, but then it quits. I tried adjusting, but nothing helped, so I went back to the original carb.
If I very slowly pull the throttle, it will take a bit more, maybe 10% more, than the high idle, but then quits. The same with easing off on the throttle, it quits almost immediately. As long as it is on high idle, it will run all day.
Adjusting the mixture screws does have an effect, with the saw slowing down as you turn a screw in or out, with a sweet spot at about 1.5 - 2 turns.
I haven't done a compression test, (can't find my gauge) but compression seems good going by the tension on the pull cord.
One other point; this carb has the extra butterfly on the top to allow extra air. Could it be getting too much air? Why have they added that butterfly?
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