97 m750 high pitched whine ? (Video samples)

[mattym750]

My early 750 makes a high pitched whine that I'm curious about. I noted it in some youtube vids before I bought, so I figured the bike wouldn't blow up. Also, my local cycle shop guys didn't comment on it when they helped me unload the bike. I forgot to ask what they thought as I was so excited to ride.

It occurs any time the engine's running and is loudest on the left; it's so loud you hear the noise rather than the exhaust when riding. It has a constant pitch but its speed varies with engine RPMs. The volume varies only slightly with RPM. Bike has ~13000 miles, 12000 mile service recently completed.

My cheapo camera couldn't capture the noise but here are the youtube videos it's clearest in:
Ducati Monster 750 exhaust
Venta de Ducati monster 750 carburadores
Best example, can hear over aftermarket cans even:
Ducati Monster 750 1996

I'm guessing it's some quirk of the early bikes, but I'm hoping there's something I can do to reduce the volume of the noise to enjoy the exhaust tone like people behind me can. Thanks in advance for any light you can shed.

- Matt in El Paso
PS I did some searches on the board here for "whine," "high pitched" etc but nothing seemed pertinent. I have heard some newer Monsters which, while they had some crazy loud clutches, didn't have any high pitched noises like this. If I missed a thread, forgive me.

[Howie]

Diagnosing a wine over the internet is iffy at best.  Some wine is normal, but, if your video is close to reality, that is not.  I suggest you try and isolate the noise by using a long screwdriver as a stethoscope.  Since the noise is coming from the left I suspect at might be the bearing in the left side case.