Author Topic: Annoying buzzing (Read 1704 times)

q2418130103p · « **on:** May 21, 2018, 04:28:15 PM »

So I realize this is probably something stupid, but I have this incredibly annoying buzzing at about 3000rpm on my cb550. Sounds like a washer rattling on a loose bolt.

I can't for the life of me find what it is, but its super annoying. Any thoughts?

EDIT - I think the sound is coming from below the gas tank, or from the top of the engine. Its very hard to tell. Its certainly not from behind me though. And it is engine rpm dependent for sure, not speed.

EDIT 2 - picture:

kaptainkid1 · « **Reply #1 on:** May 21, 2018, 04:37:15 PM »

My front fender had two loose rivets which was making a rattle sound. My bike is all stock so do you where the sound is coming from? Front of bike? Engine? Rear of bike? Is your bike stock? Did you delete the box etc.... a picture of bike would help too.

q2418130103p · « **Reply #2 on:** May 21, 2018, 04:44:40 PM »

o, oops, that was a silly omission.

Sounds like its coming from below the gas tank, or from the top of the engine.

DaveBarbier · « **Reply #3 on:** May 21, 2018, 05:02:20 PM »

Check your headlight bezel. Maybe as you ride start grabbing stuff to see if you can muffle it.

madmtnmotors · « **Reply #4 on:** May 21, 2018, 05:28:08 PM »

Quote from: DaveBarbier on May 21, 2018, 05:02:20 PM

Check your headlight bezel. Maybe as you ride start grabbing stuff to see if you can muffle it.

+1

The upper pivot screw where the inner headlight ring joins the outer bezel (not the three screws on the outside) was loose on mine and would buzz away. I thought it was the fuel door, but it wasn't until I reached out and put my hand on the headlight bezel that I was able to quell the buzz. Mystery solved! At least for me anyway...

q2418130103p · « **Reply #5 on:** May 21, 2018, 05:29:43 PM »

Cool, I'll give it a shot

Tews19 · « **Reply #6 on:** May 21, 2018, 07:45:56 PM »

Can you post a video?

scottly · « **Reply #7 on:** May 21, 2018, 08:29:37 PM »

Gas tank rubbing against the frame?

seanbarney41 · « **Reply #8 on:** May 21, 2018, 08:38:08 PM »

going through an extremely similar situation with my gs1100 right now

q2418130103p · « **Reply #9 on:** May 22, 2018, 02:40:02 AM »

if its not the headlight then ill try to get a video

rotortiller · « **Reply #10 on:** May 22, 2018, 03:36:19 AM »

You know what ignition pinging sounds like right?

q2418130103p · « **Reply #11 on:** May 22, 2018, 05:05:23 AM »

Crap, well I think it sounds quite a bit like this... But this sound is incredibly regular.

I'm running 93 octane, cr29s, high lift cam, ported head, higher compression 600cc pistons... Sounds like a pretty good recipe for knock. I'll pull the plugs, check the static timing.

EDIT - so this is a new build. there's only about 100 miles on it. I pulled the plugs early on and they were very dark, but that was with sort of a lot of idling. Its certainly possible that its too lean at higher RPM, although I haven't heard of many people having a lean problem with CR29s on a CB550.

EDIT 2 - I've never expireirnced knock on a small displacement engine before, not that I know of at least. I'd decribe this sound as much more of a high pitched buzzing rather than a rattling or knocking.

DaveBarbier · « **Reply #12 on:** May 22, 2018, 06:23:21 AM »

I’d bet it’s not knock. I don’t see how that would get confused with a buzzing at a specific rpm.

rotortiller · « **Reply #13 on:** May 22, 2018, 06:35:34 AM »

Maybe and normally I'd agree not however we are not riding the bike. Discretion is the better part of valor as they say, especially with a fresh expensive performance build. I like to be sure about things that can cost me big dollars plus I do not bet on the unknown.

ekpent · « **Reply #14 on:** May 22, 2018, 07:50:31 AM »

My funny story was I had a scary sounding 'buzzing' sound on my 1981 CB900F I could hear it while riding at a specific RPM. I was concerned it was a cam chain or something as that is where the sound seemed like it was coming from. When I got back from a ride and decided to really check it out I started it up and really starting looking around with my helmet off holding it round that RPM. I was very relieved when I discovered it was coming from the right hand mirror. The glass was loose in the housing and I could actually rotate it around in there. New mirror and all was good.

Mr. Mike · « **Reply #15 on:** May 22, 2018, 11:38:54 AM »

Don’tcha hate things like this?!
Looking at your pics, here are my observations;

*The seat pan looks very close to the tank (only rubs when you’re sitting on it?)
*The cable routing and available space under the tank appears tight,
*The support bracket for the headlamp bucket; got good clearance there?

Maybe you’ve checked each of these, if so, look at the lame stuff like the horn bracket or something inside the headlight bucket.

As Dave said, try running the bike at buzz speed, the pushing, pulling or whatever you can do safely to either change or eliminate the noise.

PeWe · « **Reply #16 on:** May 22, 2018, 01:03:52 PM »

Speedometer?
My speedo had sounded as a bad ball bearing in the engine 4 years ago. Removed cable, oiled it inside with oil spray and let it sit upside down for a few hours.
It returned a few days ago, this time only sprayed with lithium oil spray with cable off. did not remove the speedo. Lets see if that will help.

q2418130103p · « **Reply #17 on:** May 22, 2018, 02:03:35 PM »

Hmm, I don't have a speedo but I should probably try unplugging the tach. It actually stopped working right the other day, occasionally reading low.

It's going to be raining here the next couple days.

q2418130103p · « **Reply #18 on:** June 04, 2018, 01:37:48 PM »

Quote from: DaveBarbier on May 21, 2018, 05:02:20 PM

Check your headlight bezel. Maybe as you ride start grabbing stuff to see if you can muffle it.

So besides the spare bolt I was storing that was causing a lot of noise, the rest of the noise went away after I stuffed a paper towel in the headlight bezel. Thanks.

flybox1 · « **Reply #19 on:** June 04, 2018, 01:52:15 PM »

is it a dangling/vibrating key?

q2418130103p · « **Reply #20 on:** June 04, 2018, 01:53:26 PM »

Thats a good guess, I have had that. But in this case it was a 'spare bolt' that I guess I was keeping for sentimental reasons, and the headlight bezel.

DaveBarbier · « **Reply #21 on:** June 04, 2018, 03:59:38 PM »

Quote from: q2418130103p on June 04, 2018, 01:37:48 PM

Quote from: DaveBarbier on May 21, 2018, 05:02:20 PM
Check your headlight bezel. Maybe as you ride start grabbing stuff to see if you can muffle it.

So besides the spare bolt I was storing that was causing a lot of noise, the rest of the noise went away after I stuffed a paper towel in the headlight bezel. Thanks.

Glad it worked out. The hollow shell just acts as a resonator so when there’s a buzzing noise that’s the first place I check.

DaveBarbier · « **Reply #22 on:** June 04, 2018, 04:01:57 PM »

Quote from: q2418130103p on June 04, 2018, 01:53:26 PM

Thats a good guess, I have had that. But in this case it was a 'spare bolt' that I guess I was keeping for sentimental reasons, and the headlight bezel.

You just have to let go. I know it hurts but it’s better for the both of you.

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Author Topic: Annoying buzzing (Read 1704 times)