The past couple of days i have noticed a high pitched whining that seems to be coming from the top end of my 2000 twin cam. does anyone know what it could be?

 

As I have discovered recently, noise travels extremely well within the HD motor. A noise that I thought was definitely engine noise (top end specifically) ended up being primary related. I had to replace my clutch hub bearing. I can now detect what suspect is the inner primary bearing. The top end is nice and quiet.

Neil
RDMC

 

Nothing in the top end spins, everything reciprocates one way or another. The associated noises would be tapping, clunking, knocking, no whining. The closest you could come would be a pulsing whistle from the crank case vent.

 

Well, no doubt it is my wife. No, as I was, she is in the living room. Carry on.

 

With your engine running, use a short piece of rubber hose as a stethoscope to help track noises.

Have you had your cam chain adjusters checked or replaced?
Might be time.

 

The most likely candidate for making a "whining sound" from the primary area would be the primary chain. Very common when the chain tensioner ratchets up a little too tight. Pull the outer primary cover off and look at the chain. You want about 4/8" to 5/8" slack in the chain.

 

He's got a 2000. The primary chain adjuster is manual, and almost never needs to be touched, worth checking the chain play, though. I'd be most worried about the cam chain tensioners. A beast to check, but much much worse to blow one.

 

With that bike age check cam chain tensioners