Buzzing noise after riding.

[Canuck623]

I have a buzzing sound (intermittent) in my 82 CBX after I ride for a while and get the engine fully warmed up. History, I have replaced the clutch plates and springs, alternator was not charging so I replaced the brushes in the holder. After the brush replacement it started to charge the correct voltage after it is warmed up a bit. Noise occurs after traveling for several miles and then decelerating to a stop in first gear with the clutch lever pulled in. It is fairly loud and sounds like it is coming from the left side of the engine. Revving engine will cause it to stop and it may start up again but most times it doesn't occur again until the ride and stop scenario is repeated. It doesn't sound like any rattle I have ever heard. Best I can describe the noise is holding a piece of plastic against the fins of a car alternator while it is running. Anyone heard of this before? Thanks for any help you can send my way.

[daves79x]

It is for sure your alternator clutches slipping. Chirping is a better description. Could be a couple of things. Your clutches may be worn past the original shimming's usefulness. Adding a steel shim or two may help. But first measure your spring and if it is less than 30mm, then it has sacked and shimming for that can help. If the plates and spring are blue, then everything's gotten hot and needs replaced.

Replacing the two alternator bearings when changing brushes is a good idea. A dragging bearing will cause clutch slippage and will eventually fail, locking up the alternator and doing significant damage. You need to completely disassemble the alternator and evaluate each component and see what's not right. You'll need the two bearings and seal, available about anywhere, and a gasket, but from Honda they're NLA, try TIMS here in the US.

Dave

[Rick Pope]

Dave's advice is spot on. Replace the bearings whenever you need brushes. The outer bearing is a 6201 and the inner is a 6203, available at most auto parts stores where the guy behind the counter knows what points are. I don't recall the seal size, but it's also a common item, available at any bearing house.

Let us know when you're ready to remove that outer bearing, and we'll send you the instructions, only read with the secret ICOA decoder ring.

[Canuck623]

It is for sure your alternator clutches slipping. Chirping is a better description. Could be a couple of things. Your clutches may be worn past the original shimming's usefulness. Adding a steel shim or two may help. But first measure your spring and if it is less than 30mm, then it has sacked and shimming for that can help. If the plates and spring are blue, then everything's gotten hot and needs replaced.

Replacing the two alternator bearings when changing brushes is a good idea. A dragging bearing will cause clutch slippage and will eventually fail, locking up the alternator and doing significant damage. You need to completely disassemble the alternator and evaluate each component and see what's not right. You'll need the two bearings and seal, available about anywhere, and a gasket, but from Honda they're NLA, try TIMS here in the US.

Dave

Thanks for the advise. I wouldn't call my noise a "chirp" noise though. It is a definite buzz. Much like the way I described it. Plastic on fins at a high speed. I have just sold the bike to a collector and will pick up a couple of bearings that I will send along with the bike just in case though. Thanks again. The buzz remains a mystery I guess.

[Jeff Bennetts]

Just a shot in the dark but have the cam-chain adjusters front and back been adjusted lately, if not it's only a 1/2 hour job with minimal tools.

[Canuck623]

Just a shot in the dark but have the cam-chain adjusters front and back been adjusted lately, if not it's only a 1/2 hour job with minimal tools.

Don't think that is my issue but it wouldn't hurt to check it for the new owner anyway. Thanks.