Plastic discs between fins on heads

[suzyj]

I occasionally find little black plastic discs on the garage floor, and have always wondered where they came from.

Today, while cleaning the horrid brown caked on discoloured goo off my front cylinder, I found out.  They're between the cooling fins on the heads.  I can see where the couple that I found on the floor belong.

I'm wondering if they're perhaps something that was supposed to be removed when the bike was unpacked.  I don't see that they serve any purpose, aside from obstructing airflow.

So should I remove them?

[rockaduc]

I asked the service manager at my local dealer the same thing a few years ago.  His answer was "No, don't remove them.  THey are there to..."  I forget the reason he gave me, but I still have not removed 'em.

[ungeheuer]

I believe they're there to prevent the fins from resonating - a kinda sound deadening for the anally retentive.  I mean how much resonating could the cooling fins make really?  That said, since Ducati went to the time, effort and expense to place them there I have no intention of removing mine.

[monstermick58]

I believe Ungeheuer is correct, I didnt remove mine, they removed themselves, as far as I could tell I didnt notice any difference, if you have a look around you will probably see that a lot of the 2 valvers have lost them.





                                           Mmick

[Buckethead]

At one of ducvet's seminars a couple last year he mentioned working on a bike that was "pinging," sounding like it was pre-detonating. Turns out all of the discs were gone, either removed on purpose or they all just fell, and it was just the cooling fins.

Apparently it can get pretty loud, but no, it's nothing to worry about.

[RAT900]

I heard the ringing was the reason but always wondered if they were inserted during manufacturing to prevent fins from getting busted so easily from rough treatment during transport and handling

[CairnsDuc]

Duc Droppings! 

[Howie]

Your Duc is just marking its territory. 

The discs are to deaden sound.  No need to put them back, they will fall out again.  No need to remove them, they will remove themselves.

[suzyj]

Well about twenty or thirty fell out today.  I went for a ride this evening, and between the discs falling out and cleaning much of the brown goo off the front head, the oil temperature has dropped by fifteen degrees celcius.

And it doesn't sound any different.  I'll keep them in a bag in case it gets noisy.  In the meantime, I'm appreciating the lower oil temps.

[junior varsity]

Your Duc is just marking its territory. 

The discs are to deaden sound.  No need to put them back, they will fall out again.  No need to remove them, they will remove themselves.

+1.

It will "ring" with them all out, and sound more like an old school bike. They are placed there because the gov't says it can only be so loud. If the bike is 'ringing' than the exhaust must be quieter, and the intake must be quieter, etc. So there in there so that they didn't have to quiet down the rest of it (as much).

[scduc]

This topic always get me going. I to was once dumbfounded by the little gray disks. 10 years ago when I first noticed my 750 doing it, I thought WTF. then I read a topic and someone said they were there for the heating and cooling cycles to keep the fins straight ( prevent them from warping all to he**.) I now just look at them as a simple reminder that " I own a Ducati". [moto]

[rule62]

There's a great post on TOB about "mini hockey pucks".  It's pretty amusing.

[junior varsity]

duck droppings.

[NorDog]

I've looked and looked but I can't find any of these things on my S4RS.

[/troll]

[scott_araujo]

+1.

It will "ring" with them all out, and sound more like an old school bike. They are placed there because the gov't says it can only be so loud. If the bike is 'ringing' than the exhaust must be quieter, and the intake must be quieter, etc. So there in there so that they didn't have to quiet down the rest of it (as much).

Yep, noise damping.  It's the same with the little quilty blanket on the bottom of the tank, it just damps the intake noise.  Take it out and there's a little more 'honk'.  It's also the reason that the SV650 has a little circuit (which everyone bypasses) that makes it run a little leaner at low revs in 1st and 2nd gear.  I think it's the Euro standards of noise while going by at a certain speed in a certain gear.  All those little things you do let you make the actual exhaust louder so you can get a little less back pressure.

They dry out over time and shake loose.  Just let them fall out as they want to.  If it gets ringy later you can always shove them back in with some high temp silicon or something else to keep them in place.  I had a Kawaski ZR-7 that used to leave them around too.

Oh, and the S4RS is easier to housebreak than the 2V Ducs, so it tends to leave them out on the road rather than in the garage.

Scott