[SOLVED] Honda rattling sound 4500 - 5500 rpm [VIDEO]

[hornet_guy]

Hello guys,

I have a 2018 Honda CB650F with 18k miles and this thing is bothering me a lot. From the first day I got it second hand I noticed a rattling sound from the top right of the engine in the range of 4500 to 5500 rpm. Outside of this range, everything sounds OK.

- The rattle doesn't change pitch with RPM.
- Only between 4500-5500 rpm.
- Happens in every gear including neutral.
- With or without load.
- Timing chain tensioner checked.

Video:
(Seems like it can only be noticed with earphones, sorry. Also in person is more noticeable).
https://www.veed.io/view/d8aa2891-b50a-4102-93d6-3cb4e08225c5

What do you think? Could this be an issue?

Thank you.

[RhynoCZ]

Is something loose? Could be vibration related.

Sounds sort of like a loose exhaust baffle.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[hornet_guy]

[RhynoCZ]

Is the motorcycle still under warranty? If so, let the dealer have a look.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[hornet_guy]

[B1N]

It sounds like it might be a harmonic vibration, It could be a heat shield rattling or a baffle loose in the exhaust.

[xX-Alex-Xx]

Cam chain? Does it get worse if you rev higher then let off the throttle?
____________________
DILLIGAF

[hornet_guy]

[stinkwheel]

Does it go away if you pull in the clutch?
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[hornet_guy]

[Copycat73]

the only suggestion i have is there an engine mount / bolt loose ?
____________________
Whatever I post I have no citation and no intention of providing one..
caveat emptor

[Kawasaki Jimbo]

I couldn’t pick out the noise even with my new super-duper* ear-buds.

Still, if it’s limited to a 1000rpm in the mid-range I’d agree with B1N and say something is meeting its resonant frequency, which a bit of support or a tightened bolt should address.

*damn, maybe they’re not so super.

[hornet_guy]

[stevo123]

My guess is the cam chain tensioner is on the verge of clicking another tooth of tension to the guides. It is not a sound I find alarming and with it being a very narrow band likely to be something not serious.
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Honda XL125-Yammy DTR125-Honda NSR125-Yammy TZR 250-Aprilia RS125-KTM RC 125-
KTM RC390-Kawasaki Ninja 636-KTM Duke 390

[hornet_guy]

Thank you guys for your answers. I found the right upper engine mount not as tight as it should be but that didn't was the cause.

According to my last tests I'm almost sure the chain tensioner is the fault here. Now the dilema is going for a OEM replacement or a manual one... What would you do? This is a modern 2018 bike, maybe it's worth giving a try to the OEM one...

[stevo123]

Price them up, either will be fine. If manual be careful to not overtighten things and you'll be reet.
____________________
Honda XL125-Yammy DTR125-Honda NSR125-Yammy TZR 250-Aprilia RS125-KTM RC 125-
KTM RC390-Kawasaki Ninja 636-KTM Duke 390

[Nobby the Bastard]

Or you could just take out the tensioner thats in there and see if it works.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[hornet_guy]

[xX-Alex-Xx]

[hornet_guy]

Just in case it's helpful for someone, after installing and testing a new tensioner I confirm it was the problem. The rattle is 100% GONE. I inspected the old one carefully and I really couldn't tell anything's wrong with it... But now I'm completely sure it was faulty.

[Copycat73]

[hornet_guy]

[xX-Alex-Xx]