Walbro SDC Carburetor Repair And Service
Walbro SDC Carburetor Manual and Parts List for the correct identification, repair and service of the SDC series carburetor found in trimmers and blowers. View free online images or download the full Walbro SDC Carburetor Manual PDF which can be printed or saved on any suitable device. Clear diagrams and information to help in parts ordering or repair of this Walbro SDC series carburetor. Identify all component parts of the Walbro carburetor.
Walbro SDC Carburetor Manual
The Walbro model number is stamped on the body of the carburetor.
Walbro SDC Common Problems
The small filter on the fuel-intake side clogs. Clean it out by removing and spraying carb cleaner through in the opposite direction of normal fuel flow. Re-insert using a pencil eraser.
The float diaphragm degrades and reaps havoc on tuning, especially the low-end and idle.
The internal needle valve WILL leak when they get old or worn out. If you notice gas dripping from your carb, or if the idle gets unreliable, replace the needle valve and adjust the lever even with (or slightly below) the carb housing if you don’t have a gauge.
The fuel pump membrane gets stretched and/or sometimes hardens from the gas. It needs to be replaced occasionally. If your pump doesn’t pump properly, (1) it will be hard to start (2) it will tend to run lean, and opening the needles won’t help much if any.
Erratic idle or no idle is often traced to a bad internal needle valve, bad float diaphragm, bad pump, and most common… crap in the carb. You may also have an air leak!
The pop-off pressure is out of the normal range. About 12 PSI is normal. Pop off pressure is how much pressure is required to pop the main-jet needle off of its seat. The fuel pump pushes fuel against a spring. Either having the wrong spring, a cut spring or stretched spring can affect this pressure.
Walbro SDC Carburetor Manual and Parts List PDF
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