Rattling noise in Honda CBF125

[BenjaminThoma...]

Hello! I'm new to these forums.

I recently bought a Honda CBF125, it's not new but it's also not too old. I've ridden a couple hundred miles on and on starting it today I noticed a metallic rattling sound when I rev the bike. Here's a video https://youtu.be/8viU0gHw-xc
Once I'm in gear and above 4000 rpm, the sound goes away.
I'm a bit worried about my little bike. Does anyone know what this sound is and how to fix it?

Thanks in advance!

[Rogerborg]

It's hard to tell from a video. Could be epic clutch rattle, but it doesn't sound healthy. Does pulling the clutch in make any difference?

First though: have you checked the oil level? Ignore any service history or what you've been assured about it, CBFs have got a reputation for guzzling all their oil in short order and going bang.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[BenjaminThoma...]

I've just tried pulling the clutch and it makes no difference to the rattle. The oil level is also fine. Would you say it is still okay to ride, or will I potentially do damage to the engine?

Thanks for your advice.

[BenjaminThoma...]

Update.

I've had a really good listen and I think the sound is coming from the exhaust, not the engine. Which is good I suppose. The bike only rattles when I increase the revs. If I hold the rpms steady, there's no rattle. Could it be that some fucker has put a stone or something down my exhaust? I first noticed the rattle when I got on the bike after leaving it parked in my school all day. It was completely fine in the morning.

[Beehive Bedlam]

Check for loose bolts and make sure the exhaust collar isn't the source of your distress.

[Rogerborg]

Or an internal bolt or rivet or a piece of the catalytic converter is rattling around in there. It's entirely possible, it does sound like a loose piece of metal.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[BenjaminThoma...]

Thanks a million guys. I'll take the exhaust off tomorrow and see if I find anything in there.


Cheers!

[BenjaminThoma...]

Okay, so I couldn't get the exhaust off the engine because it was comletely rusted to the engine. So instead of taking the exhaust off, I took the bike to a steep hill and redlined it. By the time I got to the top of the hill the rattle was gone. The stone was shot out like I hoped.

Thanks for all your support!

[Rogerborg]

Awesome ghetto fix.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike