Strange Noise Upon Decel

[blue04fjr]

Recently, my '04 has begun to exhibit a very strange noise. Only when it's still cold in the mornings and only upon decelleration, it makes a sound that's very similar to a beer tab flopping around in a plastic box.....sorry, but that's the best way to describe it. Again, it only happens when it's cold and only upon decel. The sound disappears when the bike warms up and never comes back until the next morning.

Any ideas???

 

[ionbeam]

What you describe is the time period in which the reed valves are in operation, the noise is likely to be associated with their being active. The reed valves job is to induct air into the exhaust to help burn off any excess fuel caused by 'choke' operation. The reed valves are on a common plate with 1 reed per cylinder.