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What is the easiest way to increase the sound of a 2010 F4 without spending $$$$ :thewife:
 

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Unconnect the valve down near the rear brake!
 

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I too would like to know. I played with the nuts on both sides of the valve but couldn't get the valve wire off to save my life. Which bolt(s) need to be undone?
 

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I removed 2 bolts and a small plate - let the cables just hang there and you will see them open and close when your start the bike.
 

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Can you be more specific? There is one main big nut in the middle where I would guess the valve itself sits flanked by the two nuts on either side where the wire is. Should we unscrew both nuts and then the wire will slide off? Those nuts were a bitch to turn. I can post pics late tonight if that will help when I get off work.
 

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I will try and take a pic today it was6 months ago when I did it.
 

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It is to keep decibel noise down for noise laws undet 4000 revs or ???

I haven't noticed any difference in any area such as performance or fuel consumption.

Sorry will try and get pics today!
 

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I am assuming that when the cable is disconnected the valve stays open, would this be correct?

thanks
 

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I wonder if the difference in sound is akin to when you hit 5K RPM and you both hear and feel a slight surge. I played with revs a good bit today and noticed 5000 is were the low end comes to life. Does keeping the valve open effect that? Also, would you say you are now content with the sound decibels or is this just a temporary fix until an after market exhaust can be put on? Do they not make a cat delete for the bike yet?

Where are the pics man??? I'm off work tomorrow and want to get this done!
 

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The valve 'fails' open. I think the valve is closed at idle and low rpms, after that is when it opens. So when disconnecting the cables, it stays open all the time.

It defiantly louder at idle as I've can hear side by side with dads bike that has not had the mod done.

Even though people will argue if it affects performance at low rpm. I cannot notice any difference at all. I really think its there to dampen noise it idle.

As for removing the cables. You should not have any problems at the valve end as you can see everything (remove the exhaust heat shield). At the other end is a bit more tricky as its very confined, hard to see, cant get fingers in, etc. Some people remove the tank to get access more easy, but me and others did it by pushing on the cables to line up the cable with the exit slot of the servo and used a screw driver to dislodge the cable. In the end it was very easy, but its fidgety. Keep your cool, haha.

Have a read here too. More information.
http://www.mvagusta.net/forum/showthread.php?t=45994
 

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Any one having any luck getting this done with out pics?
 

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I removed 2 bolts and a small plate - let the cables just hang there and you will see them open and close when your start the bike.
Make sure not to leave it hanging while the bike is on. The exhaust will melt the tips when hot.
 

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The exhaust butterfly valve is designed to perform 2 functions:
1. To reduce noise by changing the length of the sound wave exiting the cylinder. The purpose of this is to meet noise regulations; and
2. To add a little back pressure in the cylinder at low revs. The purpose of this is to reduce the amount of unburnt fuel at low revs due to cam overlap and therefore reduce the amount of conversion required in the catalytic converter - reduced emissions.

Leaving the valve open will not improve performance to any measurable degree but may have a placebo effect on the rider.

By all means - do it for noise...for aussie riders - note that this is just another method to pick up a ticket...at least you will know how to fix it for the follow-on EPA tests...
 
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