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Discussion Starter #1
I had an issue recently with my 312R, after a track day at Phillip Island I ended up with a bit of oil in the airbox and my bike didn't want to start the following day. So I'm looking at these:

http://www.designcorse.com/shop/mv-agusta-parts/mv-agusta-f4-parts/mv-agusta-f4-750-1000-312-1078rr/f4-racing-accessories/f4-racing-vent-caps-detail

However I'm concerend that blocking the vents could cause other concerns, pressurizing of the crankcase etc.

Any one using these or have experience using these? I searched, but couldn't find anything specific.

Thanks

Mat
 

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Discussion Starter #4
Thanks Guys, I had overlooked that breather at the gearbox. I'll go ahead and block the vents on the cam cover. Cheers boys.
 

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Uhhhhh......boys, those are the second air system caps. They aren't "breathers".....and all Euro3 bikes have them.

The hoses come from a solenoid that is controlled by the ECU. The solenoid is connected to a clean air area of the air box. Under the caps are reed valves that allow air flow only downward into passages in the head. Those passages feed into the exhaust ports.

The purpose is to introduce clean air into the exhaust stream to help finish burning the hydrocarbons from combustion. Generally on initial decel overrun.

A second function is to help heat up the catalyzer for more effecient operation.

The "race kit" or Corse ECU doesn't utilize the second air system, so the solenoid never opens. Removing all the plumbing reduces a bit of weight, but has no performance gain. Without the Corse ECU you may find more after fire without the second air system.

Oil in your air box did not come from the cylinder head cover. Hate to say it, but Design Corse is mistaken in their description.
 

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I hear you Ed, especially on the origin of the oil.
As for the cam cover breathers, Mat doesn't need these on his bike, he's got Microtec ECU and no Cat.
So this might be a good way to start finding the problem, while loosing a lot of un-needed plumbing.
 

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I hear you Ed, especially on the origin of the oil.
As for the cam cover breathers, Mat doesn't need these on his bike, he's got Microtec ECU and no Cat.
So this might be a good way to start finding the problem, while loosing a lot of un-needed plumbing.

They're NOT breathers.....let's use proper terminology. They are the second air passages. And you are right that he doesn't need them with the MicroTech, if it hasn't been set up to control the solenoid (very unlikely).

I just put some rubber vacuum caps on mine with the existing hose clamps. Discarded everything else.

Leave the reed valves inside, though, even if you buy the block offs. The chamber they cover ports into the exhaust so there will exhaust gasses blowing up into that chamber without the valves.
 

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They're NOT breathers.....let's use proper terminology. They are the second air passages. And you are right that he doesn't need them with the MicroTech, if it hasn't been set up to control the solenoid (very unlikely).

I just put some rubber vacuum caps on mine with the existing hose clamps. Discarded everything else.

Leave the reed valves inside, though, even if you buy the block offs. The chamber they cover ports into the exhaust so there will exhaust gasses blowing up into that chamber without the valves.
Okay, no need to shout, I'm not Noel.
Very easy to set this up on the Microtec ( NOT MicroTech :thewife:).

Are you sure about the ports Ed, I'm not, so just asking for clarification.:)
 

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Dons, I wish you and Noel would quite bashing each other when there is no need.
You both contribute very important information.
The tiff you two seem to be airing is bothersome.
 

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The tiff you two seem to be airing is bothersome.
I agree Chuck, and have reached out to Noel on more than one occasion, with no response whatsoever. None.
I do apologise, and will shut right up.
 

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I wouldn't be so quick to dismiss the engine vents as the source of the oil. My little thumper KLX crank vent feeds oil into the air box. Pools a fair bit over time. Thumpers have less equal pressure than a 4, so this might not be so notable on the MV, but if the pressure is up, it might be getting more into the box. Just a thought.
 

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Oil in the airbox only comes from one source...the crankcase breather vent. Several possibilities for excessive oil in the airbox:
Too much oil (overfilled)
Wrong viscosity oil (too thin)
Long periods of running at high rpms (the KLX on the highway)
Excessive crankcase pressure (piston ring sealing).

A small amount of oil mist accumulation is quite normal. Pools of oil is not normal.

Yes Donsy, I am very certain about the second air system design, layout and function.
And it was a spell check thing that did the Microtech mistake...sorry.
 

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Yes Donsy, I am very certain about the second air system design, layout and function.

Thanks Ed, I do realise that you are far more involved in this stuff than what I am, I was just wondering more about the MV specific application, I've had a few cam covers off and can't seem to remember seeing the ports you mention on any MV F4 or B4. Not doubting you, I've just never heard of it on the 1st Gen MV'S, ahhh, but wait.

And it was a spell check thing that did the Microtech mistake...sorry.

Hahaha, I just had to get one back at you mate :), please
No worries Ed, hopefully somebody can help us with pictures.
 

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Found it Ed ... Thanks

Sorry to put you through all of this my friend, and all of this while you're on honeymoon, and prepping for Bubba 5, this is why I come to this forum, guys like you know so much more that us mortals.

Mat....... I hope you're paying attention.:)

Here's some pics of the cam covers from a 312R which drove me crazy, the ports Ed mention can be seen quite clearly, the cam cavity has naught to do with this system.
The pic of my pre EURO3 motors show the difference clearly.

My only question is this, I know, and have seen many members on the forum, block these covers in the years gone bye, anybody else have any feedback about the after affects ?

I hope I'm right, getting a bit tired of saying "sorry" all the time.
 

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Donsy...no problems mate.

Blocking off the second air system has zero affect on performance. Might create a little after fire in the pipes from accumulated unburned hydrocarbons igniting...always on decel, occasionally on sudden throttle opening or gear shift with an ignition kill quick shifter (that pop race bikes make when changing gears under full throttle accel).
It's an emissions device, but affects emissions after the power is made, not while it is being made.

Anyone thinking they got more horsepower on their Triumph, Kawasaki, whatever, when they blocked off that system is a sadly confused individual.

And it is not on the Euro2 MVs.....
 

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My only question is this, I know, and have seen many members on the forum, block these covers in the years gone bye, anybody else have any feedback about the after affects ?

I hope I'm right, getting a bit tired of saying "sorry" all the time.
Since it seems Mat's questions has been answered I can provide some feedback on the affects of block off plates. I installed them on my CBR, more commonly known as PAIR (Pulsed Air Intake Reed) delete. The only real reason I installed them were for tuning purposes. The theory is you will have a more accurate reading. As far as day to day riding you don't notice a difference.
 

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Since it seems Mat's questions has been answered I can provide some feedback on the affects of block off plates. I installed them on my CBR, more commonly known as PAIR (Pulsed Air Intake Reed) delete. The only real reason I installed them were for tuning purposes. The theory is you will have a more accurate reading. As far as day to day riding you don't notice a difference.

That is correct. To get correct A/F readings in a dyno tune you must plug them off. Most common way is to put a cork or marble in the hose while doing the tune.

The Japanese call it a "Pulsed Air" system....others call it Second Air.
 

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Discussion Starter #18
Oil in the airbox only comes from one source...the crankcase breather vent. Several possibilities for excessive oil in the airbox:
Too much oil (overfilled)
Wrong viscosity oil (too thin)
Long periods of running at high rpms (the KLX on the highway)
Excessive crankcase pressure (piston ring sealing).

A small amount of oil mist accumulation is quite normal. Pools of oil is not normal.

Yes Donsy, I am very certain about the second air system design, layout and function.
And it was a spell check thing that did the Microtech mistake...sorry.

Thanks guys for all the input here. I've certainly learnt something.

Okay, so the oil in the airbox is not as simple as blocking the secondary air ports. I will delve deeper this weekend, and blank the plates using Ed's method just for good measure.

Ed, I can rule out oil level being too high, and hopefully rule out piston ring bypass as the bike has only done 13,000 kilometers. Phillip Island is a fast track and the bike spent more time over 9,000 rpm than it ever has so I had concluded that it was due to being run at higher RPM for longer periods than normal. Oil viscosity is correct, though it has done a 3 track days since the last oil change. It's due so I'll probably do that this weekend also.....The oil is still nice and clean though.

Thanks again for the input.
 

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Mat;

put a Chore Boy pot scrubber in the breather......you have to stretch it and bend it around the divider

:naughty:
Good old racer trick......bet it was those long high rpm runs at Phillips Island.
 
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