Rattling noise near starter?

I have a rattling noise that is near or around the starter area. Sounds like something is loose and moving around.Is there any part of the starter that could be causing this. Seems to happen more when the bike is idling. And before the bike is warmed up. Sometimes the starter does not engage the first time it is fired. Thanks in advance. BIGD 1981 KZ1000 M1

It might be several things: 1. The over running clutch for the starting mechanism is loose. 2. The rotor for the alternator has a loose magnet.or 3. The bolt holding the rotor to the crankshaft is loose.

Any of these situations will require the left side enginecase be removed for inspection. Have a new gasket on hand as it will usually tear on removal.

If the bike has a center stand put it up on it and then if possible lean the bike to the right to minimize oil loss.

Have a drip pan to catch any loss.While your in there, consider replacing the three springs and rollers for the over running clutch.

Could it maybe be cam chain noise?

On my CSR M1 this noise was the 3 bolts on the starter clutch had come loose, this is a common problem on this model. If your bike clunks at low rpms or on warm up, the starter clutch bolts are usually the culprit. The bolts will more than likely be no good for further use so you will need to get replacement allen head (metric size) you can get these at NAPA auto parts in the bolt bins.
The hardest part of this repair will be getting the stator off the end of the crankshaft. Best of luck,
Grant.

Thanks Grant. The last sentence says stator, did you mean starter? And do you think it is OK to drive or should the problem be fixed now. Thanks Don

I had the same problem on my 82 KZ1100.
And it finally went out.
So unless you like to push start it you going to have to fix it.
When you take the side cover off you will see the magnetic rotor behind that is what looks like 1/2 inch thick hamburger patty and a big gear behind that.
The patty looking thing is the starter clutch.

You can continue to ride it until either you can't stand the noise anymore. or it breaks the bolts.
I did write stator, I mean't the magnetized portion of the alternator (maybe bad terminology).
The clunking noise doesn't necessarily mean that the starter clutch is not working correctly, it only tells you that it is loose from the back of the stator. The starter clutch bolts are captive in that they can come loose, but cannot back completely out. What happens is that they come loose and the noise you can hear is the starter clutch banging back and forth trying to cut the bolt heads off. When you get it apart, the bolt heads will look okay, but the threads directly below the bolt head will be mangled. Reassembly will require new bolts and a dose of loctite to ensure the new bolts don't come loose.
Grant.

Adjust your cam chain before you do anything. It's free and easy.

I have recently replaced the valve seals and the cam chain was tight and in good condition. Thanks Don

Thanks, that's great, I will get right on it. Don

The charging systems on these older bikes usually is made up with an alternator composed of windings(Stator or stationary part)and a magnetic rotating part(Rotor) attached to the end of the crankshaft.

Through magnetic lines of force,an Alternating Current is created by the action of the magnets on the Rotor acting on the windings of the Stator.

This Alternating Current is changed to Direct Current through rectification at the Regulator/Rectifier, charging the battery and running the bikes electrical system.