Due to the engine vibration and heat cycling of the pipes, all owners should be prepared to deal with this, usually at the worst time. Running with a blown gasket isn't a problem short term, but the noise is not always pleasant to the rider or people around the motorcycle. Getting in front of this is best handled by checking the two crossover clamps on a regular basis as well as the crossover to muffler clamp. The two joints in the first photo are the most problematic.
Exhaust Gasket (Cross over x2) Guzzi #GU06123500
AF1 racing ($26)
MG cycle ($23)
Kawasaki part will also work ($12)- #11060-1330
Exhaust Gasket (Head to pipe x2- not usually needed) Guzzi #976376
AF1 racing ($6)
Exhuast Gasket (Cross over to Muffler x1- not usually needed) Guzzi #GU05128230
AF1 racing ($40)
MG cycle ($39)
Below is viewed after you are aware of the problem. The problem begins fairly quickly (noise) and the gasket will be gone in less than a mile of riding.
The gasket is not found after pulling the pipe apart.
The right side gasket was this problem. This procedure can be used for both sides.
Remove O2 sensor- This will make getting the pipe fully out much easier. Follow the connector from the O2 sensor, unplug connector, re-route wire, and remove from head pipe.
Remove the two nuts/washers that retain the headpipe. Be careful not to damage the head exhaust gasket by pulling straight out. Be careful not to damage the gasket on the studs or frame.
The cleaned up pipe, O2 sensor removed, and new gasket. The cross over pipe may need to have the female section opened up to allow the gasket to fit. I used an adjustable wrench to carefully open up all four flanges evenly. The gasket should slip in with little drama. The clamp should go on next prior to placing the pipe back in.
Get everything in line, tighten the head retainer (make sure the retainer is in the correct direction- see other side), and tighten the exhaust clamp last. Place the O2 sensor back in place, re-route the wire, replace connector, and replace any tie-wraps that were removed. The O2 wire runs by some suspension parts, so be aware of any interference.