My 5th gen is making a strange sound. It only makes the sound when the clutch is pulled and the bike is on gear. The sound seems to come from the area around the head stock. It sounds like electrical crackling or shells from pecans. It only happens with the clutch pulled and the bike in gear. I listened with a stethoscope but found nothing. I guess I need to check the air cleaner for nuts but you would think it would make the sound all the time.
Hi Jim, been there, done that. You are hearing the electrical solenoid that drives the vacuum for the flapper valve cycling on/off. For whatever reason, the flapper is closed in gear below 5500rpm UNLESS the clutch is pulled in. If your clutch switch is making intermittent contact (and if you have aftermarket adjustable levers this is more likely) when you are sitting in 1st gear at a standstill, you'll hear an electrical buzzing sound. My suggestions (1) don't panic (2) try adjusting your clutch lever out by one click (3) hit the clutch switch with contact cleaner.
I post what I think is an obscure problem and "boom" someone has an answer . I will do as you suggest tonight and report back. Thanks!
Mine does this too, thanks for posting! 'Pecan shells' is a perfect description of the noise, at first I figured it was the speedometer cable wearing out and then I learned our bikes have electronic speed sensors so that ruled that out. As Big Jim did, I checked everything I could think of, found nothing that logically could be the cause of such a noise. Didn't think of a solenoid making intermittent contact, but it makes perfect sense now that you mention it.