If I've got this right, the exhaust baffle is open at tick over, and closes up when the revs rise ? Is that correct, as it kinda sounds the wrong way around ? Wouldn't you want it closed at tick over to keep it quiet, and open up at hi revs when you need to get the exhaust gases out quicker ? Its on "to do" list in spring time to check/clean/lubricate this item as I read they can cause problems. Cheers
The flap valve is, in effect, a noise emissions cheat device. It closes at the part of the rev range that the noise test is done at and then opens again once through that zone. The primary silencing is in the cat box. the OEM muffler is straight through and does little to nothing in the way of noise attenuation. Some owners have gutted the cat but most find this obnoxiously loud. You can disconnect the actuating cable or drill out the screws holding the flap to it's shaft. Disconnection is the easiest but will result in an error on the dash, you need to to wire the valve open and then either fit a spring to the end of the actuating cable or fit an exhaust servo eliminator into the loom to fool the ECU into seeing a functioning servo motor with the required physical resistance.
Or fit an exhaust valve eliminator which keeps it open all the time and prevents the warning light showing...
@pcn1 My only youtube video and it's about this very topic. I've since installed a Duc.EE servo eliminator.
I'm going to sound like a grumpy old git here but..... I find the bike a bit loud at tick over on the driveway, I'm surprised it passed any euro noise test ! Its an old age thing chaps
One of the few bikes technically banned from some Austrian passes due to Db level. https://fliesonthevisor.com/austria-and-motorcycle-noise/
You would think those restrictions would go against the Euro compliance. As most here knows, this topic is dear to me as I've developed Ducatinnitus from my Panigale even though I always wore ear plugs. The Monster is loud although not as severe as it projects rearward. A loud Multistrada would sit somewhere in the middle. I have measured the stock MTS 1260 decibels and documented here: https://www.ducatiforum.co.uk/threads/multistrada-exhaust-decibel-readings.73847/
For the elimination of the flapper valve; not so much a power advantage as it's fully open at all but a critical point in the rev range, might even be gear specific too, that coincides with regulations and where they test for noise emissions. However, as far as I perceive anyway, it does smooth things out when riding at lower speeds, such as around town. Doing it using a spring is a simple job and costs next to nothing. Just remove the black exhaust cover (3 cap headed Allen bolts), remove the cable, wind spring into the end* and wire open the valve. * I didn't use this technique, used a Healtech Eliminator. You may need a couple of small washers and a hacksaw to cut slots in them to locate the ends of the spring against the cable outer and the cable nipple. Have a look here. The majority of owners do this mod due to the flapper valve sticking, it will most likely do this at some point, rather than for any performance gain.
As Bumpkin says, it’s more maintenance than anything else. But it does improve low down sound and ime it runs a bit better low down too
