Originally Posted by BarelyAWake
BTW - the primary reason for spring-clamp exhaust is to isolate the exhaust system from engine vibration. Not uncommon to see on other small 2-strokes like snowmobiles, ultralights and others. It's usually a ball and socket joint - but with longer exhausts and high vibration the metal can fatigue and crack over time, particularly if unsupported.
I learned that 40 years ago building exhausts while converting snowmobile engines for aircraft use. "Loosey Goosey" and "Flexy Wexy" is the key. SBP recommends against welding the copper joints for just that reason.
That's why I think a lot of these guys who are just welding up pipes are barking up the wrong tree.