CB650R Buzzing / Resonance Noise 5.5K to 6.5K RPM ('19 CB650R)

[Devilsfan]

If you follow the Service Manual it should be pretty easy. I know I always cringe a little when I hear plastic popping but so far, on all my bikes, I've never broken a plastic tab. As for those plastic clips, you can get some from the dealer as a "just in case" but they're generally a few dollars more per clip. Or, you can find some on Amazon in bulk for pretty cheap! (Always good to have a few extra!)

I'd say to just finagle the best you can getting in there. Sometimes you don't have to remove the plastics to get in somewhere, at least not all the plastics.

I'm still thinking your annoying sound is something else. Either that or you're hearing something that's normal...but it's stuck in your head and it's driving you nuts! (Been there, done that!) I mean, thinking that it's more present at higher RPM's would suggest something spinning, maybe metal on metal.

But...see what you can do with tightening up that bolt and report back.

 

[thatyanguy]

I'm still thinking your annoying sound is something else. Either that or you're hearing something that's normal...but it's stuck in your head and it's driving you nuts! (Been there, done that!) I mean, thinking that it's more present at higher RPM's would suggest something spinning, maybe metal on metal.

Normally I'd be inclined to agree, but the specific noise sounds almost like a frequency specific resonance if I'm using the term correctly. I've dealt with similar noises before but usually it has to do with speakers hitting a specific note causing something in or around the mounting to vibrate, which is why I'm thinking it's that bolt cause it's the only loose piece of metal I can find. Either way - I have one more attempt in me (not sure If I'm going to pull the shroud - work space is not ideal). I've reached out to the other just as crappy dealer in the area and asked them to specifically quote the work required to tighten those bolts - we'll see what they have to say.

Anyways, hoping to have some kind of final resolution by the end of the week.

 

[rev_and_break]

Normally I'd be inclined to agree, but the specific noise sounds almost like a frequency specific resonance if I'm using the term correctly. I've dealt with similar noises before but usually it has to do with speakers hitting a specific note causing something in or around the mounting to vibrate, which is why I'm thinking it's that bolt cause it's the only loose piece of metal I can find. Either way - I have one more attempt in me (not sure If I'm going to pull the shroud - work space is not ideal). I've reached out to the other just as crappy dealer in the area and asked them to specifically quote the work required to tighten those bolts - we'll see what they have to say.

Anyways, hoping to have some kind of final resolution by the end of the week.

Hey! Do you have an update on your issue? I also noticed on my bike that there is a buzzing noise when I'm in 1st, 2nd or 3rd gear and I was really curious where does the sound come from. It's very hard to debug this issue while riding and also while stopped.

 

[RAFHonda]

Hey! Do you have an update on your issue? I also noticed on my bike that there is a buzzing noise when I'm in 1st, 2nd or 3rd gear and I was really curious where does the sound come from. It's very hard to debug this issue while riding and also while stopped.

I'd also be interested, I've got the same issue/noise in 1st and 2nd. Bike has done 6000mi/10000km and was serviced at 600mi in September last year. Noise appeared at about 2000mi/3000km.

 

[thatyanguy]

Hey Guys,

Sorry for lack of update - long couple of weeks here. Here's what I got:

1) I've basically given up troubleshooting. The fartherst I've done is pull the air intakes completely off to get access to the bank-angle sensor, which does wiggle around in its mount but when I tried tightening the bolts, I couldn't even get them to move with the tools I managed to fit in there so it's clearly not that loose.

I still think the resonance might be coming from there / that general area. The only other guess I have is that something has loosened (as is natural-ish) over time with all the vibrations and such, and now at specific resonance frequencies it fires off that buzzing sound. I'm guessing it's most noticeable in the lower gears since there isn't as much competing noise to drown it out.

I was never able to pin-point an exact source or fix it, and as you saw before my attempt to have Honda look at it were extremely disappointing. Decided to just live with it for the rest of the riding season as it appears to be a "cosmetic" issue only and the bike still rides just fine. Might be trading it in for a Street Triple next year or just accept that this is a very buzzy bike; depending on how things go with COVID Winter Edition (TM).

But if anyone has any ideas, I'm still open to trying to remedy it - I've just given up my own self guided attempts, but I'm glad I'm not the only one - nice to know I'm not completely crazy.

 

[RAFHonda]

Hey Guys,

Sorry for lack of update - long couple of weeks here. Here's what I got:

1) I've basically given up troubleshooting. The fartherst I've done is pull the air intakes completely off to get access to the bank-angle sensor, which does wiggle around in its mount but when I tried tightening the bolts, I couldn't even get them to move with the tools I managed to fit in there so it's clearly not that loose.

I still think the resonance might be coming from there / that general area. The only other guess I have is that something has loosened (as is natural-ish) over time with all the vibrations and such, and now at specific resonance frequencies it fires off that buzzing sound. I'm guessing it's most noticeable in the lower gears since there isn't as much competing noise to drown it out.

I was never able to pin-point an exact source or fix it, and as you saw before my attempt to have Honda look at it were extremely disappointing. Decided to just live with it for the rest of the riding season as it appears to be a "cosmetic" issue only and the bike still rides just fine. Might be trading it in for a Street Triple next year or just accept that this is a very buzzy bike; depending on how things go with COVID Winter Edition (TM).

But if anyone has any ideas, I'm still open to trying to remedy it - I've just given up my own self guided attempts, but I'm glad I'm not the only one - nice to know I'm not completely crazy.

I'm sorry to hear that you haven't resolved it. Reading about the car park troubleshooting technique has motivated me to find a quiet enough stretch of road to investigate further. I'll report back if I make any breakthroughs!

 

[Smoky Mountain Rider]

So I just stumbled across this post. I just got the noise vibration frequency also today. Only difference is that I took off my mirrors. Now I hear that frequency around the same rpm. Sounds like it’s coming from the ignition area where the key is. I only have the bike key in the ignition. Very strange, seems like the mirrors have added some extra weight in the handle bars and never heard it till I took them off. I just put them back on and will do a test ride to see if the frequency went away.

 

[Krobus]

I just got my CB650 a few weeks ago with 3 miles on it, and immediately noticed when I got it into the 6-8krpm range in 1-3 gear that I had the same metal on metal buzzing. So I highly doubt it was from anything coming loose, unless my bike came off the lot with something already loose. Which I highly doubt with Honda.

Like a few people mentioned, for the longest time I just thought it was the key ring, until I took it down to just the key itself. But I swear that's exactly where the sound is coming from! Could it be the key itself in the socket, or maybe the pins in the lock? But there's no way of testing that... I mean, unless you hotwire your own bike. Another thing I thought it could be is maybe the horn...?

Either way, thanks for bringing up this issue. It's been driving me nuts too.

 

[Smoky Mountain Rider]

Ok I’m 99.9% sure it’s the key in the ignition and the pins inside it. I hit those buzzy rpms and I could see the key physically vibrating at the high frequency. Not sure how to stop this or if we can stop it.

 

[thatyanguy]

I just got my CB650 a few weeks ago with 3 miles on it, and immediately noticed when I got it into the 6-8krpm range in 1-3 gear that I had the same metal on metal buzzing. So I highly doubt it was from anything coming loose, unless my bike came off the lot with something already loose. Which I highly doubt with Honda.

Like a few people mentioned, for the longest time I just thought it was the key ring, until I took it down to just the key itself. But I swear that's exactly where the sound is coming from! Could it be the key itself in the socket, or maybe the pins in the lock? But there's no way of testing that... I mean, unless you hotwire your own bike. Another thing I thought it could be is maybe the horn...?

Either way, thanks for bringing up this issue. It's been driving me nuts too.

I think you're 100 percent right. I did a teardown of the intake (to a point) and checked everything I could find in there, couldn't identify the source as documented. The pins in the ignition make sense, as that is EXACTLY where the noise seems to be coming from (as the other recent response pointed out).

I'd call that case closed, and no I don't think we can do anything about it. I'm happy with this conclusion, still irritating as hell but oh well. Even the Honda dealer said "it's a very buzzy bike and some people don't like that".

I think, based on reasonableness, that the best way to counteract this is to get the exhaust nice and loud so it drowns out the buzz. Akra with no baffles group buy ?

 

[bfoster80]

Ok I’m 99.9% sure it’s the key in the ignition and the pins inside it. I hit those buzzy rpms and I could see the key physically vibrating at the high frequency. Not sure how to stop this or if we can stop it.

I think you are exactly right. Mine does the same thing, buzz from the key at 5k up. Maybe put some rubber between the ignition and where it mounts?

 

[JH09]

use / add different keychain? maybe it will add some weight to the key or something. just spitballin' here, guys. trying to help solve this. i had what i think you are describing happen once, briefly. can confirm was annoying

 

[Atucker]

I just noticed something incredibly odd with the buzzing. When I purchased it new at the dealer they noted it had premium fuel and that I should continue to run 93 octane. I did for a few tanks until I confirmed the manual stated to use 87. I switched and never really thought much about it. I've put close to 1000 miles on it now and had mostly forgotten about the buzzing. I attributed it to just getting used to bike and it settling in. Well as winter approaches I decided what the heck maybe 93 would hold better during the time I am riding less. Well the buzz is back and its unbelievable. Exactly as intense as new and unmistakable. How is this even possible? Is it possible that there's a correlation between octane and engine buzz? I would have argued with anyone for even suggesting it until now and feeling my bike literally the second I pulled away from the gas station.

 

[thatyanguy]

I just noticed something incredibly odd with the buzzing. When I purchased it new at the dealer they noted it had premium fuel and that I should continue to run 93 octane. I did for a few tanks until I confirmed the manual stated to use 87. I switched and never really thought much about it. I've put close to 1000 miles on it now and had mostly forgotten about the buzzing. I attributed it to just getting used to bike and it settling in. Well as winter approaches I decided what the heck maybe 93 would hold better during the time I am riding less. Well the buzz is back and its unbelievable. Exactly as intense as new and unmistakable. How is this even possible? Is it possible that there's a correlation between octane and engine buzz? I would have argued with anyone for even suggesting it until now and feeling my bike literally the second I pulled away from the gas station.

Interesting - it's possible. A long, long time ago I had a 2.0L K20 Civic SI and you could 100% hear the difference in the engine based on what kind of gas you put in it - in Canada, my options were 91 (recommended) and 94. There was a difference in tone and smoothness between even different providers 91 gas - for example, I found Esso made it a bit more "raspy" than Shell. I attributed it to the fact that Shell (at least at the time) was not blending any ethanol in with their gas. Now that you mention it, I do generally put Petro-Canada gas in this year since their pumps have contactless payment, whereas last year I believe it was mostly Shell, but not exclusive. Either way, I think it might be possible as the buzzing does seem to be related to resonant frequency - different fuel could lead to different combustion, etc. That being said, I have always fed the bike 91 octane gas.

Do you instantly get the buzz though? Because I can completely avoid it if I stay below that RPM range, so when you say "the second I pulled away from the gas station" this suggest a buzz at a different RPM range so yours could be something different.

 

[thatyanguy]

use / add different keychain? maybe it will add some weight to the key or something. just spitballin' here, guys. trying to help solve this. i had what i think you are describing happen once, briefly. can confirm was annoying

I'm putting the bike away for the year - too cold now, but maybe next year I'll try zip-tying some weights to the key. Don't really want to add a key chain that will fly around and rattle in the wind. Or maybe just live with it, I dunno. BIke has been fine otherwise (it is a great bike and I love the way it handles), so maybe just throw in the towel and hope my OCD finds something else to latch onto.

 

[bishop]

Paired Valve causing the noise?

Do you guys have it removed or still installed?

 

[Atucker]

Interesting - it's possible. A long, long time ago I had a 2.0L K20 Civic SI and you could 100% hear the difference in the engine based on what kind of gas you put in it - in Canada, my options were 91 (recommended) and 94. There was a difference in tone and smoothness between even different providers 91 gas - for example, I found Esso made it a bit more "raspy" than Shell. I attributed it to the fact that Shell (at least at the time) was not blending any ethanol in with their gas. Now that you mention it, I do generally put Petro-Canada gas in this year since their pumps have contactless payment, whereas last year I believe it was mostly Shell, but not exclusive. Either way, I think it might be possible as the buzzing does seem to be related to resonant frequency - different fuel could lead to different combustion, etc. That being said, I have always fed the bike 91 octane gas.

Do you instantly get the buzz though? Because I can completely avoid it if I stay below that RPM range, so when you say "the second I pulled away from the gas station" this suggest a buzz at a different RPM range so yours could be something different.

I instantly felt something different, not bad, but definitely different. The buzzing wasn't until around the 5500 - 6000 rpm range and was so much more pronounced that if I hadn't been sitting on the bike I would have believed it was swapped. To be clear in my case its not like something is wrong or it's bad gas. The bike runs fantastic, but the buzz is much more pronounced after the octane change.

 

[bishop]

Where is the demand valve located?

I don't know what pared valve means.

All 650's - PAIR Valve Removal

Updating from old site as a few people have enquiries about the mod: Reasons For: Throttle is buttery smooth all the way up and down the line in all gears. No garbled noises or stutters on deceleration just smooth linear transitions. Approx 6 hours maximum to complete. It's a simple mod in...

650f.bike

 

[bishop]

This video can explain it better.

I could hear it rattle at idle, when I installed my new exhaust. Removing them got rid of the noise.

 

[jey153]

This video can explain it better.

I could hear it rattle at idle, when I installed my new exhaust. Removing them got rid of the noise.

I don't make that sound at idle, I start to make more than 4000 RPM. I'm talking about the noise from 15 seconds above YouTube video.