This was very useful post.
I just recently purchased a demo 2009 8v that has 1500 miles on it. It has (had) a Term pipe with the baffle removed. Well on the first ride home, I got caught in a heavy rain storm. Apparently, the spark plug failed in the left-hand cylinder and as I rode the bike for about 2 miles to get to cover at a gas station, the Term pipe was fried by unspent fuel. Bummer. (Guzzi is replacing the pipe.)
The dealer has since worked on the bike to fix the spark plug and put the stock pipe back on while the new Term pipe is delivered. I took it home the next day, but it just didn't ride "right". At minimal throttle opens and cruising aroung 2,000 - 4,000 RPMs, the bike seems to shutter and "miss". The other very puzzling thing is, when coasting a to a stop, occassionaly there is a high pitch whistling sound coming from the right-hand side head. The bike starts, sounds great, runs great under open throttle, but when you back off the throttle to just "cruise", things are less than smooth.
I have owned many bikes and in fact have two others sitting in my garage (2008 - Concours, 2007 - Trimph Speedmaster); but this is my first Guzzi and don't have a context for how this bike should feel. It is slight consistent bucking normal? The occasional high pitcah whinning sound can't be normal.
The guys at the shop have asked if they keep the bike until they sort this out. Any ideas what this could be?
The owner of the motorcycle dealership is a real stand-up person and has offered to give me my money back; but I really love the bike and he gave me great deal on it since I have purchased other bikes from him in the past.