Walbro and Jacks Small Engines both provide free diagrams available for all models of Walbro carburetors. Each company has a parts number cross-reference tool on its website as well, identifying replacement parts, gasket sets and complete rebuild kits.
The most common Walbro carburetor part problems are degradation of the float diaphragm and wearing of the internal needle valves, both of which cause poor idling and rough running. If the problem is multiple parts, and a gasket replacement or rebuild is necessary, Pegasus Auto Racing has step-by-step instructions on the proper disassembly, rebuild and resealing of automotive carburetor models. OutdoorPowerInfo.com has complete tutorials on maintaining and rebuilding Walbro small engine carburetors, such as those for single cylinder engines and two-stroke motors.