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Discussion Starter #1
am doing a service on my 2013 Brutale 1090R and noticed that the pipe that a hose plugs into (bottom front of airbox - see breakout in pic #18) is blocked with a 6mm bolt and sealant
the parts list says its a 'connector, pipe secondary air'
have seen references to this system in the forum, but not sure what its for or whether it should be blocked
 

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The secondary air system allows air into the exhaust ports to help with burning the residual hydrocarbons coming out of the combustion chamber. It's an emissions control used on just about every bike and car today.
It has absolutely nothing to do with horsepower.
Regardless, many people remove the system for various reasons. In my case it was removing plumbing that gets in the way of valve cover removal......and of course, tiny bit of weight loss.
So the question is, did whoever plugged the air supply also plug the inlet spigots on the valve cover and remove the solenoid that opens the passage for air?
 

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Do the 1st Gen (F4) bikes have this also?
 

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Discussion Starter #4
esq'z me, thanks for the info
i bought this bike with a full arrow system - no cat - and power commander and autotune, so maybe that has something to do with it
 

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Discussion Starter #5
i'll pull the tank off again and check whether other things are blocked, the plumbing is still there
 

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i'll pull the tank off again and check whether other things are blocked, the plumbing is still there
If the plumbing is all there and not blocked off then you are getting dirty air into the exhaust ports with the possibility some will be pulled back into the cylinder with reversion affect during overlap (sound wave pushing escaping fresh mixture back into cylinder as intakes open and exhaust close). :wtf:
 

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Discussion Starter #8
i haven't got back to the garage yet, but after looking at the parts diagram, i'm a bit confused
the line from the air box goes to the solenoid and from there 2 lines go to inlets with reed valves on top of the valve cover
how does any air get from the valve cover into the exhaust port?
 

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i haven't got back to the garage yet, but after looking at the parts diagram, i'm a bit confused
the line from the air box goes to the solenoid and from there 2 lines go to inlets with reed valves on top of the valve cover
how does any air get from the valve cover into the exhaust port?
The valve cover is a go-between for holes that go through the cylinder head to the exhaust ports.
 

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You can use rubber vacuum plugs. 12 mm fits I think.

Or you can make a plate that replaces that part on the valve cover, just capping it off.

I think there are some available from aftermarket.

AL- made up some from carbon fiber. He generously provided a set for me and that is what is on my 910R.
 

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?

ecosmeri;
Make some aluminum plugs to fit inside the hose mounts and epoxy them in, the rubber caps
kept cracking and then the motor would blow oil vapor out, making a mess

:wink2:
 

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Îm sorry i dont understand the part with oil vapor?

You mean if it put plug in hoose this will make some trouble with oil vappor?


The epoxy is to fixe it it the hoose or your means paint epoxy to protect the aluminium?
 

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Lets see if i have understand( my english is not really good):

I machined some caps in aluminium to put it into the hoose with epoxy that they could not moove ( i think i will use hoose clamp).

For the oil vapor, i could have it in the intake (airbox, intake pipe) if i not put the caps in this hoose?
 

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There are reed valves under the caps on the cylinder head that only allow air to flow toward the exhaust port. There is no oil anywhere in the system. You do not need to worry about oil.

If you do not plug the inlet to the cylinder head the consequence will be unregulated air flow into the exhaust, which will result in lots of after-fire pops and bangs in the exhaust system. That air will also be unfiltered, which means dirty air is entering the exhaust port.

The ECM controlled solenoid only allows air flow when appropriate to assist with burning residual hydrocarbons in the exhaust gasses, reducing emissions.

It is more important to plug the air cleaner box connection for the hose to the solenoid. This is an opening to the air box after the air cleaner and so will allow dirty air into the intake tract.

I had rubber vacuum caps with hose clamps on my Brutale cylinder head cover inlets for years with no deterioration. The only reason they are not there now is because I got these lovely carbon fiber plates.

You should leave the reed valves in place regardless of your chosen plug method as they prevent hot exhaust gasses from reaching the vacuum plugs or block off plate.

The only valid reason to remove the second air system is weight reduction, or getting plumbing out of the way for maintenance access. There is no power gain or advantage.

I would not add a plug in an existing hose, as I would be trying to get rid of all the hoses. Less is better in this case. Plug the inlet with a vacuum cap. Or machine a blocking plate. Or buy a block-off plate from an aftermarket supplier.

The best method wold be to remove the valve cover and seal the passageway from the exhaust port.
You could then just leave the reed valves and caps off entirely....or get a pre-Euro3 cylinder head cover that did not have the second air system.
 

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Ok thank you for your answer. I don't want to remove the entire systeme just want to block the injection of cold air in the exhaust. So i let all the hoose, reed valve, reed valve cover in place. I just insert in the hoose connected to reed valve cover, a plug to stop air flow in it, but if i understand for you it'e better to do it directly in the hoose attached to the airbox? Is it right?
 

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Are you removing the solenoid?

There is no reason to disable the second air system unless you are removing everything possible related to it.

The air box connection MUST be plugged to prevent dirty air entering the engine.

It is a simple matter to put vacuum caps on the cylinder head cover spigots. Purchase at any auto parts supply.

You can just unplug the electrical connection to the solenoid if your objective is only to stop the function of the second air system. Or you could insert a ball bearing into the hose from the air box, stopping air flow.
,
But you will gain nothing.

The only reason to disable the second air system is minor weight loss, or removal of items that interfere with removing the valve cover for services.
 

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No i not remove the solenoid. I want deactivate to not have fresh air in exhaust that could damage the exhaust valve.

and also to see if it could solve my probleme of hint under 4000rpm.
 

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@ecosmeri: You are going to a lot of trouble for something that will produce limited, if any, change. Leakage in the intake tract MAY produce some hunting; but, by-and-large, the hunting is a combination of poor tuning and poor adjustment (balancing) of the throttle bodies.

Take the time to first - find any intake tract vacuum leaks, second - balance your throttle bodies, and third - have your ECU tuned in the low rpm range. My 1090RR exhibited similar characteristics, as did my F4 312R, UNTIL the ECu was tuned.

Unfortunately, due the state of tune for these bikes from the factory, hunting, especially when cold, below 4000 rpm is normal.
 
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