What is this bit (RD04)

[AlanH]

On my project RD04 I noticed a hole in the side of the airbox snorkel with a clip attached. Looking at the fiche here:
http://www.xrv.org.uk/RD04_FICHE/rd0..._target39.html
...it seems part 19 is missing.

Now, having taken the other RD04 apart to do some electrics, I notice it is present on the other one - but what does it do? It seems like it has two chambers with an outlet on each one but they are not connected to each other. The only thing it seems to do is stop the CDI falling off its mounts. The project RD04 seemed to run fine without it.

Is it Honda's idea of a joke item like a crankshaft endfloat or a bag of replacement valve clearances or does it have a function?

[BobA]

Alan

This one's been touched on before, and I seem to remember that general concensus was that the big empty bit of plastic thingy was some sort of sound deadening object possibly.

People seem to remove them to hide alarms in that space.



Bob

[anton88]

Its a resonator chamber to smooth/balance the airflow in the airbox i think. Ive taken mine out and never had any problems

[AlanH]

Thanks guys. It will remain missing in that case

[Zenarchy]

Its a resonator chamber to smooth/balance the airflow in the airbox i think. Ive taken mine out and never had any problems

Yep, that's what it is. I took mine out a while back too to leave a bit of space under the seat for electrics and wiring in an alarm and haven't noticed a bit of difference since I did it.

I think it's meant to create turbulence in the airflow though rather than smooth it out (been a while since I looked it up so may be mistaken) but I seem to remember that being something to do with it. Regardless it doesn't seem to have effected the bike at all since I took it out (or if it has I haven't noticed yet).