One of the most likely places for problems to appear is the tuned pipe and muffler. They usually revolve around vibration and cracking from heat.
Exhausts usually have two parts, the tuned pipe and silencer. A few, like the box muffler of the long-retired Solo 210 have no tuned pipe. Tuned pipes are shaped so as to maximize power, or reduce fuel burn at the same power. Tuned pipes usually have some baffling inside and the silencer has some form of packing to reduce noise.
Exhaust systems endure a brutal existence. High temperature and high vibration make cracking a common problem and welding is rarely a long-term solution. When parts break or let loose, the prop is there for them. It rarely survives the encounter.
Below are some of the problems commonly found.
Most engine’s have an aluminum head with studs sticking out. Those studs are, of course, themselves screwed into the head and if the exhaust is over tightened against the head you will strip out the head threads. Also, if the bolts/nuts get loose they will allow the pipe to set up a resonance that can strip out the thread. Either way, you’ll need to repair the thread.