What manual would you refer to for adjusting idling speed and mixtures for a specific engine?

The engine manufacturer's maintenance manual is the appropriate resource for adjusting idling speed and mixtures for a specific engine. This manual typically contains detailed specifications, procedures, and specifications specifically tailored for the engine model in question. It covers all critical aspects, including recommended settings for fuel mixture and idling speed, ensuring that adjustments align with the manufacturer's standards for optimal performance and safety.

The engine manufacturer's maintenance manual is designed to provide the most accurate and relevant information needed for maintaining and servicing the engine, which is essential for achieving desired operational characteristics. It can also include troubleshooting tips and guidelines for adjusting various components based on specific engine tuning requirements.

While other resources like fuel system maintenance manuals, carburetor service guides, and aircraft operational manuals might provide useful information, they are generally not as targeted or specific as the engine manufacturer's maintenance manual for engine adjustment tasks.