Exhaust leaks often occur at the cylinder exhaust ports where the exhaust riser flanges attach. Leaking exhaust quickly erodes the soft aluminum at the exhaust port, necessitating costly cylinder removal and reconditioning. Exhaust leaks are easy to spot. They leave telltale red, orange, or yellow stains. Inspect for them every time you preflight.
Most pilots operate their engine much too rich.
Lean as aggressively as the book allows. For cruise climb, lean to 125 F rich of peak for best power and extra cooling. Lean during all ground operations except for engine start. It is particularly important to lean for taxi and runup. Since EGT is usually low-offscale at idle power, the best method is to lean for peak RPM at idle.