The symptoms are less severe, but the troubleshooting continues...
I sprayed carb cleaner all over the butterfly valve and the throttle block, then soaked the cylinder as well. Carb cleaner's pretty cheap!
When I took the plastic liner off the throttle block (the liner is under the priming bulb on top of the throttle block) a little gummy chunk of resin came off, so that was worth doing.
I added Sta-Bil to the weedwhacker's fuel tank and our two-stroke gas can.
30 minutes later I put everything back together and started pulling on the weedwhacker's start cord. After 103 pulls the cylinder had finally cleared out the carb cleaner and the engine began turning over. It ran pretty smoky for a couple minutes (on full choke) but finally warmed up.
It runs great when the butterfly valve is shut, and it runs even faster (max RPM) when the butterfly valve is opened a little. But when I move the choke lever from "full choke" to "run", the weedwhacker still shuts down. I get a little bit of leeway if I'm quick on the choke lever but it really isn't sustaining its combustion.
A few hours later it occurred to me that I'd cleaned the heck out of the priming orifi, the air inlet, and the cylinder. However I didn't exercise the throttle while I was spraying the carb cleaner, so if there's something gummed up in the throttle pipeline then it's probably still there. I'll take a new look at that another day.
The plastic handle on the pull rope broke apart from all the pull-starting. I still have enough to work with but a new weedwhacker is looking like a strong possibility.
I sprayed carb cleaner all over the butterfly valve and the throttle block, then soaked the cylinder as well. Carb cleaner's pretty cheap!
When I took the plastic liner off the throttle block (the liner is under the priming bulb on top of the throttle block) a little gummy chunk of resin came off, so that was worth doing.
I added Sta-Bil to the weedwhacker's fuel tank and our two-stroke gas can.
30 minutes later I put everything back together and started pulling on the weedwhacker's start cord. After 103 pulls the cylinder had finally cleared out the carb cleaner and the engine began turning over. It ran pretty smoky for a couple minutes (on full choke) but finally warmed up.
It runs great when the butterfly valve is shut, and it runs even faster (max RPM) when the butterfly valve is opened a little. But when I move the choke lever from "full choke" to "run", the weedwhacker still shuts down. I get a little bit of leeway if I'm quick on the choke lever but it really isn't sustaining its combustion.
A few hours later it occurred to me that I'd cleaned the heck out of the priming orifi, the air inlet, and the cylinder. However I didn't exercise the throttle while I was spraying the carb cleaner, so if there's something gummed up in the throttle pipeline then it's probably still there. I'll take a new look at that another day.
The plastic handle on the pull rope broke apart from all the pull-starting. I still have enough to work with but a new weedwhacker is looking like a strong possibility.
