Here's a new one.....

Ok, so I rode my kz750 to work this morning and something I've never heard happened. It was cool out about +2 not sure what that is in American....Ha! Anyhow was doing about 60 and all of a sudden this hum started. Like a dremel tool was on touching the tank. The only way I can describe the sound. So I geared down for a turn and it went away. I came back up to speed that I was at and it came back? Stopped at a light and it went away. Didn't lose power or anything else just the noise. When the light turned green I gave it some gas and no noise? It went away.
I know the cam chain needs replacing but this was a first for me as far as this noise went. I just put new tires on the bike last week and I checked to make sure nothing was hitting the fender or rubbing anywhere.
This is a first for me, so I was wondering if anyone may have an insight on what this may be.
Thanks in advance.
BD

This happened to me too, drove me crazy... I found that the rubber supports for the tank had gone hard and shrunk. These are the rubber disks that your tank slips over up by the steering neck. The tank would vibrate at certain RPM's. I took some electrical tape and wrapped it around the rubber pieces then slipped the tank back on. No more vibrating noise...
Hope this helps.
Grant.

Grant, Thanks man!!!! It threw me for a second. Never had I heard this type of sound in all my years of riding and wrenching. Glad I'm not losing it and not the only one who has experienced it.
I've got spare rubber mounts I'll replace em.
Thanks again man!!
BD

I've had that kind of noise from time to time. Last time was when the bolt holding the tank to the frame was loose and the back end of the tank was just touching the frame. Once it happened when my gas cap was loose.

Thanks JR. I checked the cap while I was riding, but I'll also check the bolts on the tank. Maybe one of the rubber grommets where the bolts are is also hardened up.
Thanks man. Glad I'm not the only one.