idiotwithasaw
Super OPE Member
My 550xp was giving me a little trouble, it was having an off idle bog/ slow throttle response, and would die if left to idle for longer than 30 seconds. Then required several pulls of the rope to bring it back to life, almost like it was flooding itself. Needless to say I was a little disappointed in the performance. If this was a normal carburetor most people would just lean in the l screw and go from there, but this being an autotune there are no screws to turn... Or are there. this little guy is hiding behind a brass plug masquerading as an accelerator pump.
I remembered reading a thread on Another Site about this little guy, it was never really cleared up to me where it went or what it's for, if someone else knows please chime in for all of our benefit. Anyway it was suggested that this screw be turned 1/4 turn CCW and that is what I did.
After reassembling I took it out and did some cuts and got it warmed up to operating temps then let it idle for several minutes without issue, it didn't die once. It also had throttle response you would expect out of a pro grade 50cc saw. I then let it set for a short while +/- 10 minutes and it started one pull low idle. In my lowly opinion this has fixed my problem.
This was on a walbro AT-1A carburetor, the one in the picture is a walbro AT-1 off of a 545, BUT essentially the same carb with different programing I believe.
I remembered reading a thread on Another Site about this little guy, it was never really cleared up to me where it went or what it's for, if someone else knows please chime in for all of our benefit. Anyway it was suggested that this screw be turned 1/4 turn CCW and that is what I did.
After reassembling I took it out and did some cuts and got it warmed up to operating temps then let it idle for several minutes without issue, it didn't die once. It also had throttle response you would expect out of a pro grade 50cc saw. I then let it set for a short while +/- 10 minutes and it started one pull low idle. In my lowly opinion this has fixed my problem.
This was on a walbro AT-1A carburetor, the one in the picture is a walbro AT-1 off of a 545, BUT essentially the same carb with different programing I believe.