Some Mazda MX-5 Miata owners report experiencing poor performance and starting issues following a camshaft installation, which may stem from improper alignment or functioning of the crankshaft and valve components. These problems can lead to rough idling and rich running conditions. Additionally, starting troubles can arise from various factors, including ignition switch malfunctions, weak batteries, faulty starter motors, or fuel delivery issues. Some owners have noted difficulties in restarting the engine when it is warm, indicating potential starting system problems that require attention. Regular maintenance is essential to prevent performance issues, such as sticking brake calipers, which can further affect the vehicle's performance. While the Mazda MX-5 is generally regarded as a reliable sports car, proper care and maintenance are crucial to ensuring its overall performance and reliability.