I consider myself to be somewhat of an accomplished shadetree small engine repair mechanic, but I've had two problems this year that have been kicking my butt.
First off is an issue with a Shindaiwa EB2510 (4-cycle) handheld leaf blower. This is Shindaiwa's "professional" series, purchased about 3 years ago.
Some time during the second year, the blower got difficult to run, especially when warm. At open choke, the blower would stall out quite regularly when running it at wide open throttle. At half choke, the blower still worked adequately, so I never bothered to look in to it any deeper.
This year, ran the blower once so far. Second time I went to use it, it wouldn't run unless choke was on full. I knew it was time to tear down the carb for a diagnosis.
Once I got in to the carb (Walbro WYL series), I knew immediately there was a problem:
You can see the residue caked up along the passages, diaphragms, and gaskets - I'm guessing that water in the fuel resulted in some growth within the carb and clogged the jet and/or passages up.
I cleaned it up real well (required some scrubbing to get the powdery residue out since carb cleaner was ineffective for dissolving it) and all looked good. I used rebuild kit K20-WYL to rebuild the unit and put it back together.
It actually runs real well at WOT now, but I'm still having a little trouble with idle. Once warmed up and choke is open, it will idle well but will occasionally stall out at idle. Transition from idle to WOT is a bit laggy as well. It won't still all the time, but does still frequently.
I've checked out Walbro's info on the theory of operation for this carb:
The Shindaiwa has no idle mix adjustment screws as described within Walbro's documentation, only an idle speed screw. There's a non-removable brass fitting on top of the throttle lever, no plastic plug and no black screw as described within the documentation. I'm guessing the carb is a hair rich or lean at idle but don't know of any way to adjust.
Any ideas? Only thing I can think of is to open the throttle component of the carb back up and look to see if I missed any cleaning within the throttle barrel that could be causing this situation.
Thanks in advance!