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Oil Breather Alternative

mnguzzi

Tuned and Synch'ed
Joined
Jul 22, 2014
Messages
30
Location
Minnesota
I am curious if anyone has tackled rigging up an oil breather that has a return capability. I know that V7's have a habit of dumping oil into the airbox until it gets to it's "happy place". I would like to use something like a brake fluid reservoir or coolant reservoir to act as a catch and return but I am unsure if there would be enough "breathing" with that setup. Any thoughts, ideas?
 
I am curious if anyone has tackled rigging up an oil breather that has a return capability. I know that V7's have a habit of dumping oil into the airbox until it gets to it's "happy place". I would like to use something like a brake fluid reservoir or coolant reservoir to act as a catch and return but I am unsure if there would be enough "breathing" with that setup. Any thoughts, ideas?
It would be helpful if you let us know which V7's you're referring to. The '13 and later models (1TB) seem to have this problem sorted out. I've had no oil consumption or loss on my '13 and '16 Stones.
 
Apologies, it is a '14 Stone. I have removed the air filter a couple times to find oil pooled slightly in the air box.
 
I had some oil under my air filter as well. Keep the level mid way between the marks on the dip stick. Don't over fill. With Todd's sump spacer he recommends 2.5 liters for this very reason.
 
Thanks Cam, same with all of mine including my new V7 II. Just reduce the oil level to 1.6L and you won't have that issue. Guzzi recommends over-filling them on the '13+ models to compensate for the older motors consumption. If you want a true 2.5L, get my sump spacer; https://www.guzzitech.com/store/product/gt-rx-v7-sump-spacer-kit-black/
If you want to catch it outside of the air box, there are a couple decent options on eBay for cheap, or you can vent it free-air with a K&N on top, but expect it to mist around wherever you place it.
 
I'm pushing oil into my air box to the point the paper filter would be saturated. Have since gone to a K&N filter because of this issue. Have tried to let the oil run down mid way on the stick but it still is pushing oil into the air box. When the oil enters that air box it is then sucked up into the air intake into the fuel injection system. They did design the air box with a return oil system from 2013 on but that system is not working out very well on my bike and other folks bikes. I read posts with claims of no oil in the air box and I wonder what type of riding these people are doing or they just got lucky and I must have got a damn lemon. The bike went into the shop twice since I've own it and they have been unable to figure out what is going on. They told me they see this issue all the time and Guzzi will not recognize it as an issue. I do live in California with a very progressive lemon law but I'm not the type to pull crap like that off. Sure wish someone could lead me to a fix.
 
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I'm pushing oil into my air box to the point the paper filter would be saturated. Have since gone to a K&N filter because of this issue. Have tried to let the oil run down mid way on the stick but it still is pushing oil into the air box. When the oil enters that air box it is then sucked up into the air intake into the fuel injection system. They did design the air box with a return oil system from 2013 on but that system is not working out very well on my bike and other folks bikes. I read posts with claims of no oil in the air box and I wonder what type of riding these people are doing or they just got lucky and I must have got a damn lemon. The bike went into the shop twice since I've own it and they have been unable to figure out what is going on. They told me they see this issue all the time and Guzzi will not recognize it as an issue. I do live in California with a very progressive lemon law but I'm not the type to pull crap like that off. Sure wish someone could lead me to a fix.


If you are pushing that much oil I'd be concerned that the rings haven't seated. I recommend a compression and leak down tests to check the condition of the rings.
 
They did all those tests at the shop and the bike passed with flying colors. I'm pushing lots of oil into the air box to the point I end up checking the oil every few hundred miles and it's always down 300 to 400 CC's. It went back to the dealer twice and they can't figure it out. They told me they have several other bikes doing the same thing. I purchased the extended sump so I'm not worried out on the road of running out of oil. The shop for some reason are blaming the extended sump. Can't see how that would cause this at all. The other thing they blame it on with me is the way I ride. Which is crazy because I ride easier on the street then most people, Good shop, good people, but I don't think they know much about this bike. I don't know much about it myself so it's just a total blank slate, blind leading the blind over here.
 
How much oil do you put in at a change? Let it go down the 300-400cc and don't add. With the extended sump, you still have over 2 quarts. Some bikes will push oil to a certain point then stop. See if it stops. It also sounds like you may be riding it too easy which prevents the rings from fully seating. You are building crank case pressure somehow.
 
2.5L puts it at the bottom line with my sump spacer, which is what I recommend.
 
Thanks guys. I'll try this lower fill level out and see what happens. Maybe with the extended sump and no internal baffles in this sump could be creating some type of oil splash up issue. The shop manager for some reason thinks the top line on the dip stick is too high with an extended sump..... I for the life of me can't comprehend how the fill level dip stick reading would change with an extended sump, that would remain constant in my mind. Could just be an oil sloshing around issue and that sump need some type of baffling system. That extra quart may be creating havoc. When it had the stock sump I didn't have this issue that I noticed. I'll try the 2.5 fill level and or treat the bottom line as the full line. I suppose when the oil is down to the very bottom of the stick that would probably be a half quart down or so.
 
The first line on the stick (from the bottom) I treat as a full line. The bottom of the stick is the add line. My guess is a 1/4 quart low of the 2.5L at that point (with the pan spacer). There's no splash issue, as the crank isn't exposed to the oil like the big blocks are (it's fully sealed), and the feed is gravity fed from the bottom of the pan. It's just an oil tank on the bottom of the motor really. Any pressurization issues are internal to the crankcase, which is what they supposedly "fixed" in '13, and now again with the V7 II. I still am seeing what you are. The sump spacer was used in a few V65 racing machines here in SoCal late last decade, with no issues as to pressurization.
 
Thanks Tod for the information, finely someone who knows the mechanics of this engine. Maybe the fix for this is to replace the breathing system on my bike because obviously something is wrong.
 
OK guys. I did a little study and evaluation of this bikes breather system.

Noticed that the vent hoses are one each from the heads. I can't see any type of baffling system at all. The reason is because those hoses go straight into the bottom of the air box and then you have two hoses that are oil return lines from the bottom of the air box into the sump that are vacuum operated by a one way check valve. They only drain oil into the sump when the check valve is open once the motor is turn off. (vacuum pressure closes the check valve while the bike runs) So that oil while the engine is running sits on the bottom of the air box, (IN THEORY) Because what is happening in reality the vacuum in the air box cause oil to be sucked up the forward wall of the air box and straight into the air intake system.

The theory was a good one venting into the air box with oil return lines only they should have design a type of baffle system on the bottom of the air box to prevent the oil from being sucked up the front wall of that air box and into the air injection intake pipe.

So what is needed is a baffle of some type to keep the oil trap until it can have a chance to return into those return lines once the engine is turn off. This would prevent oil loss since all the oil would return to the sump rather then only some of it.

Only thing I can't or could not see is any baffling system in the head. Hard to tell how that is routed without taking the entire engine apart or using an x ray machine. Not sure if that is a straight through system or if it is baffled somehow inside that head.

Only thing that is confusing to me is why some bikes do this and others don't do it which leads me to some type of baffling system inside the head or it could all be related to oil levels chosen by individuals.

One other thing I wonder about is the accuracy of the dip stick in the whole mess. Could be those dip sticks have not ever been properly calibrated from the factory Or they aired on the high side with the oil because of past low oil levels burning a few motors up in the past.

SO all this being said I'm trying to figure out a baffle system built into the bottom of the box that will trap the oil from being lifted and sucked up into the intake and still allows venting to take place.

Or just forget about it and enjoy the benefit of a 2 stroke oiling system. Probably make the engine last longer in the long run. At least the oil is being atomized with the fuel in the injection system, don't that beat all.
 
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OK guys. I did a little study and evaluation of this bikes breather system.

Noticed that the vent hoses are one each from the heads. I can't see any type of baffling system at all. The reason is because those hoses go straight into the bottom of the air box and then you have two hoses that are oil return lines from the bottom of the air box into the sump that are vacuum operated by a one way check valve. They only drain oil into the sump when the check valve is open once the motor is turn off. (vacuum pressure closes the check valve while the bike runs) So that oil while the engine is running sits on the bottom of the air box, (IN THEORY) Because what is happening in reality the vacuum in the air box cause oil to be sucked up the forward wall of the air box and straight into the air intake system.

The theory was a good one venting into the air box with oil return lines only they should have design a type of baffle system on the bottom of the air box to prevent the oil from being sucked up the front wall of that air box and into the air injection intake pipe.

So what is needed is a baffle of some type to keep the oil trap until it can have a chance to return into those return lines once the engine is turn off. This would prevent oil loss since all the oil would return to the sump rather then only some of it.

Only thing I can't or could not see is any baffling system in the head. Hard to tell how that is routed without taking the entire engine apart or using an x ray machine. Not sure if that is a straight through system or if it is baffled somehow inside that head.

Only thing that is confusing to me is why some bikes do this and others don't do it which leads me to some type of baffling system inside the head or it could all be related to oil levels chosen by individuals.

One other thing I wonder about is the accuracy of the dip stick in the whole mess. Could be those dip sticks have not ever been properly calibrated from the factory Or they aired on the high side with the oil because of past low oil levels burning a few motors up in the past.

SO all this being said I'm trying to figure out a baffle system built into the bottom of the box that will trap the oil from being lifted and sucked up into the intake and still allows venting to take place.

Or just forget about it and enjoy the benefit of a 2 stroke oiling system. Probably make the engine last longer in the long run. At least the oil is being atomized with the fuel in the injection system, don't that beat all.


I replaced my air filter last week and found a small pool of oil in the bottom of my air box. This is after I have taken my '13 V7 to my mate Mario, the Guzzi specialist here in Perth with some sort of fuelling issue (I've already emailed Todd about it as well...)

Lucky for me my brother has a '13 V7 Racer that lives in my garage so I popped his seat off and had a look in the Racer's filter box. Only a very, very slight film of oil coating the bottom of the box and no pooling whatsoever! Handy to have a bike that has had no known issues to compare to =)

The hoses coming out of my airbox are covered in oil and so is the Y piece that connects the two hoses together. I'm going to take them all off, clean them, replace the clamps and chuck it all back together to see if it makes any difference.

I also found a drop of oil on the lip of my throttle body intake. My "fuelling" issue is a slight hesitation at constant speed so I'm wondering if the amount of oil being sucked up by the throttle body is contributing to that...

I bought my V7 Special with 82km on the clock a few months ago, got it for a steal at a local dealer who'd had it sitting on his showroom floor since it arrived in 2013! Had the first service, have Lafranconi Competitzione mufflers and now have the BMC filter (got the BMC filter to try and trick the computer into supplying more fuel with the added air. Made a slight difference but not enough for the issue to go away completely...)

IMG 4138
 
Looks like the inside of my air box, and I also find it getting sucked into that intake as well. So the oil end up atomized into the engine. Guess I'm not the only one with this issue after all.

The low speed fueling on my bike is not very good. Herky jerky type thing. Once I get up to speed it's ok with the occasional surge or miss which I think could be from the oil going into the intake. Probably a combination of just flat out bad fueling.

I don't think I'd buy another Moto Guzzi product.
 
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Looks like the inside of my air box, and I also find it getting sucked into that intake as well. So the oil end up atomized into the engine. Guess I'm not the only one with this issue after all.

The low speed fueling on my bike is not very good. Herky jerky type thing. Once I get up to speed it's ok with the occasional surge or miss which I think could be from the oil going into the intake. Probably a combination of just flat out bad fueling.

I don't think I'd buy another Moto Guzzi product.


I've wanted a Guzzi ever since I was 7 years old! A little issue like this is no biggie for me, I know it's only a temporary issue that I'm looking forward to correcting myself. It's like when someone asks me "oh is the new bike fast!?" and I reply "no, it's more about the journey".

I was introduced to motorcycles by my '78 Honda and the Guzzi in comparison is joy, but I'm used to spending a lot of time on maintenance and restoration so I really don't mind ironing out a few issues that mine might have =) Especially when I have the support of Mario here in Perth and Todd online!

I also have an 11,000km Racer to compare everything to, I know my bike isn't broken in yet so of course they're going to feel like two different machines...

I reckon a reflash and a half fairing in the new year will do me just fine, hopefully all in time for 2016's Ride On Rooftop Bike Show!
 
I'm going to inspect my plugs tomorrow as well, see how they're doing with the little bit of oil that's being sucked up. Could be a spark issue if the plugs are fouling...

My RH plug cap was a little loose on the end of the lead as well...might have a play with that as well...
 
As has been said a few times, if your motor blows oil out the breather something is wrong and I would address that. It should not be considered "normal".
It may be an issue with the motor or it may be too much oil in the sump. But whatever it is, it is not "normal".
There is nothing weird about a Guzzi motor. They do not work under different rules of physics and engineering than other motors. And many motors do not have a method of separating oil out of the breather air, yet they don't blow oil unless something is wrong.
 
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