Many early hours in the plane I was getting CO alarms on the ground or in slow flight. Made most of that disappear with improved canopy sealing, but the engine got noisier on our month long trip around the US in June. Finally found the leak, it was due to a warped flange on #2.
Flattened it a bit with a beltgrinder, put on a new no-blo gasket, and the noise is gone.
Hans
Exhaust Leak
Linear Mode
