2013 V7 oil in the airbox

[guzziv7fan]

Find oil in my air box all the time and notice my oil level goes down a bit. Looks to me like the oil is being sucked out of the heads into the airbox by those two breather hoses coming off the heads into that air box.

I'm thinking about joining the two breather hoses with a T or Y and then installing a little K&N filter between the junction of the two breather hoses. Then block the two holes at the bottom of the airbox since I will no longer need them.

I'm thinking this would stop the oil from being sucked out of those heads and they should still breath ok with the fix. I've had this same issue on other bikes and used this type fix and it stop my oil from disappearing. I'm not using a great deal of oil but it will take the oil down to the bottom line on the dip stick after a few thousand miles about 300cc's to 400cc's usage maybe. I'm almost certain it is the design of this breather system causing this.

Any thoughts would be appreciated.

Maybe someone on here already incorporated this type fix for this breather system after finding the same issue with their V7.

Notice a third hose from the lower crank going into the airbox with some type of check valve attached. Looks like that is meant as a return of some type. Why the check valve is confusing or they did that so it can't suck the oil out of the lower half of the motor into the airbox.

The system looks somewhat well thought out but as other systems like this they often cause oil to be sucked out of the motor because you end up with a certain amount of suction created in the airbox.

[oldbike54]

Cue Vasco DG , come  in Pete  :D

  Dusty

[sib]

On the newer V7's, oil isn't "sucked" out of the valve covers.  What happens is that all engine blow-by is vented via the valve cover hoses.  It flows into a chamber in front of the air box where the oil is condensed on "filters" which are similar to the oil-trapping filters in a cooking stove vent hood.  The condensed oil flows back into the crankcase via hoses and a one-way valve.  The air in the blow-by is vented to the air box via a small (1/4") hole between the filter chamber and the air box proper.  There will usually be a small coating of oil in the air box.  If there is more, then the cause is probably a blockage in the oil recovery hoses or the one-way valve.  Overall, this system works very well to recover most of the oil in the blow-by and send it back to the crankcase, and the engine loses very little oil.  I've never detected any oil use between 10,000 km servicing intervals on my '13 V7 Stone.

[sib]

Been installing 2.5 liters with filter, have found if you go over that it pumps oil like crazy into that airbox.

Are you sure that 2.5 liters isn't too much?  With the stock sump, spec is 2.0 liters.

[sib]

So if I understand this right, what I did will not prevent the oil blowing out of the heads. So the system is design to blow oil out the heads and then recover the oil. So I could maybe just have had a blockage in that return system like that check valve deal?

Generally speaking, you can't prevent blow-by, it's an unavoidable consequence of internal combustion engines with imperfectly sealing piston rings and valve stems.  The best that can be done is to recover the oil in the blow-by stream and vent the residual gases.  That said, modern engines are very good at accomplishing this and lose ("use") very little oil.

[sib]

Re-did the whole thing.

Routed each head hose into a T and then into one hose routed under the bike out the side so as not to drop oil onto the rear tire. I'll keep an eye on it.

That recovery system was a good idea maybe but they didn't consider the vacuum in that air box which is sucking the oil out of the heads and then it won't allow that recovery system to work properly. The oil end up recovered into the intake manifold and final destination into the combustion chamber, works about as good as a Hoover. MG should start selling vacuum cleaners they got it all figured out. A little under engineered or over engineered, whatever.

I'm just a regular guy with regular solutions.

Caveman style works for me or even a bigger hammer, getter done.

I still think something isn't right on your bike, because my bike, with the identical design, doesn't use oil or accumulate it in the air box.

[Chuck in Indiana]

Re-did the whole thing.

Routed each head hose into a T and then into one hose routed under the bike out the side so as not to drop oil onto the rear tire. I'll keep an eye on it.

That recovery system was a good idea maybe but they didn't consider the vacuum in that air box which is sucking the oil out of the heads and then it won't allow that recovery system to work properly. The oil end up recovered into the intake manifold and final destination into the combustion chamber, works about as good as a Hoover. MG should start selling vacuum cleaners they got it all figured out. A little under engineered or over engineered, whatever.

I'm just a regular guy with regular solutions.

Caveman style works for me or even a bigger hammer, getter done.

<sigh> Sorry, and you will be, too. Because of the way the small block engine is designed, there is a *lot* of oil vapor flowing through the heads. Trust me. One of the lines came loose on the Lario and made a mess under the tank. You are going to be dumping a lot of oil on the ground. Guzzi just may know a little about engine design.. ~;

[Kev m]

I still think something isn't right on your bike, because my bike, with the identical design, doesn't use oil or accumulate it in the air box.

Ditto...

[Chuck in Indiana]

Thanks guys.

I'll put this back the way it was then and replace that one way check valve.

The cost of some hose is no big deal at this point.

At least the digging around is familiarizing me with the bike.

The idea of oil venting below the bike even with it off to one side is not a very secure feeling since I've gone down once before because of a vent hose spitting oil on the rear tire.

 ;-T

Thanks for the information guys.

[jackson]

You may already know this but I didn't see it in your posts (unless I missed it):

Are you checking the oil when it's hot and around 10 minutes after you've turned off the engine?  If not, you're likely to get a false reading. 

I have a V7 Classic (2010 model) that I recently purchased and I used to own a 2007 Breva 750.  I put a sump extender on the Breva and the Classic had one already installed when I bought it.  Checking the oil on the Breva 750 when it was cold would read low........down to the add line.  But if I checked it when it was hot, around 10-15 minutes after shutting off the engine, it reads just a little under full..............s o that's where I ran the Breva and had no problems.  Right after I bought the Classic, I checked the oil when it was cold and........bingo... ..........it was down to the fill line.  So, I warmed up the bike, rode it for 30 minutes, turned off the engine and let it sit for a little over 10 minutes and it was just below the "full" mark.

Thought I would throw this out if you're not checking your oil like this.