[Rossman]

So, after much searching I have come to my conclusion as to what is causing the rattle (bb's in tin can sound) at higher RPM. It looks like the roller rocker arms have about 1 mm of play between them and the machined surfaces of the head. As you get moving, they skate side to side causing this rattley sound. I'm going to call Honda Canada and mention my findings, and perhaps recommend some spring washer mod for each side. That should cure the rattle.

 

[Redline]

roller rocker arms, what are these and where do I find them?

 

[Rossman]

Rra

Roller rocker arms are in the head, under the valve cover. They are forked, and control 2 valves each (see pic).

 

[sendler]

noise not yet

So, after much searching I have come to my conclusion as to what is causing the rattle (bb's in tin can sound)

I will keep an ear out for trouble with mine but I haven't heard it yet.

 

[pgkool]

Roller rocker arms are in the head, under the valve cover. They are forked, and control 2 valves each (see pic).

Wow that is a very detailed 3d image of the engine. Is this the actual 250r engine?

 

[Rossman]

Engine

That is an actual cutaway view of the new 250R engine.

 

[Redline]

Make sure to let us know how you get on Rossman.

 

[sendler]

Neutral?

Is the noise in neutral only or while riding? I was listening to my engine this morning on the highway and there is zero tapping noise. There is a gear whine that sets in above 7000 in 6th that I will keep my ear on.

 

[Corehound]

I get a rattle at about 5.5k - 6.5k rpm then it goes away after that. Still in the break in period. Wonder of the frist service will fix this.

 

[Redline]

I have a buzzing/rattling at around 5500rpm.

 

[Corehound]

I saw another post where the owner found the cause of the rattle to be around the instrument cluster. Wonder if its the same cause for everyone?

 

[Rossman]

rattle

My rattle is around the 5500 rpm mark too, and no, it isn't coming from the dash. My friend has the exact same bike, and same noises. I'm only at 500km right now, so I don't know if it will go away. I can tell you that my valves are tighter than loose, so it's not valve tappet noise either. I'll keep you posted.

 

[lenbrinke]

Roller rocker arms are in the head, under the valve cover. They are forked, and control 2 valves each (see pic).

thats a good pix of the valves,where are the shims that may
need ajusting in the first service?

 

[Rossman]

Shims

They are under the rocker arm, at the tips. There is apparently a way to change out the shims w/o removing the cams too. See here:Remove the Shim CBR 250R should not remove the Camshaft | Daily Motor

 

[Redline]

I'm in Thailand and going for my 12,000km service next week. An American lad is the manager in the Honda dealership but the mechanics are Thai (pretty useless by default). Will get him to tell them to check out the roller rocker arms and see what's what.

If any of ye get to do the same with competent mechanics back in the western world it would be great to get the info.

 

[Rossman]

Rockers

Redline, let us know what they say.

Thanks!

 

[Redline]

I'll probably have to explain every detail of what I want done... which I don't really know myself.

What do I say or instruct them to do?

That the roller rockers have about 1mm of play between them and the surface of the head. They move side to side causing the rattling sound. And recommend a spring washer to be placed between them?

 

[sendler]

Mods

You are not going to have any luck asking a dealer to modify your valve train out of the blue. The only way they will touch it is if there is a tech bulletin on the problem which would give detailed instructions and parts information. If you can clearly demonstrate the issue to the service manager, they can make phone calls to find out what to do. You may have to go back several times and meet with a Honda representative. The people at the dealer don't work for Honda. They work for the owner of the dealer. You may have to call Honda and ask for an appointment with a traveling tech specialist.

I'll probably have to explain every detail of what I want done... which I don't really know myself.

What do I say or instruct them to do?

That the roller rockers have about 1mm of play between them and the surface of the head. They move side to side causing the rattling sound. And recommend a spring washer to be placed between them?

 

[Redline]

Alright, thanks. I'm based in Thailand and things may or may not be different here. The American guy I know who manages the Honda dealership I go to is a good and open guy. Will be talking to him in a few days anyway, so hopefully will have news to post.

Although so far this is only a theory on the internet, and no one has actually seen or fixed it with regards to the roller rocker arms. So taking apart an engine based on what might or might not be an issue might be a bit much until it's actually seen to the issue/fault.

I presume they have to take much of the engine apart to fix an issue such as this?

 

[Rossman]

Fix

They don't have to take much apart. It would be the same as doing a valve servicing. Only, as per previous link, they don't have to remove the cams to do it.