HELP ! Oil pouring out of the air filter box on 2006 Bullet

[UniqueGirl]

Any help would be appreciated.  Yesterday went for a ride and I got about 30 miles into it when I noticed oil pouring out of the air filter box.  There were no other issues with the bike.  I know that the breather tube vents to the air filter, and ALL the oil was pushed out through the breather tube.  Luckily I noticed it at a stop sign, shut down the bike and trailered it home.  So I'm pretty sure there's no damage due to oil starvation.  Now I'm just guessing here but it seems that either the oil pump failed or the oil return line is clogged.  Are there any other possibilities?  Also, how do I go about troubleshooting this problem?  Is there an easy way to determine which it could be.  I'm not a mechanic, but I have the next best thing... a friend who is fairly competent with bikes.

[Arizoni]

Is your oil fill cap the kind that seems to have two closed positions?  Some of the iron barrels had this type.

If it does, the first "closed" position is the running position.  The second, fully closed position is for shipping the motorcycle and it totally closes off the sump.

If the bikes with this type of filler cap are operated with the cap fully closed it will blow the oil out of the engine.

[UniqueGirl]

No. It doesn't have two positions. Thanks for reply.

[ace.cafe]

Okay, here's what you have to do.

Find the catch can in the engine breather circuit which near the battery box. It's a cylindrical shaped can with some hoses on it. You have to drain the oil out of it, because that's where the oil is overflowing from that is getting into your air filter.
Then, you need to remove the breather hose that comes off the top of the oil tank and goes to that catch can, and blow it all out so it's good and clean.
Next, reverse that hose so that the "L" shaped molded bend is up at the catch can, and not on top of the oil tank. You can route this over the frame tube instead of under it like the factory does.
Then clean all the oil out of the air filter housing and get a new air filter element in there.

Next, look at your oil dipstick and see if there is any whitish gunky stuff that we usually call "mayonnaise" in the oil tank. This is commonly seen in the oil tank and also the breather system because water vapor from the air condenses inside the engine when it's cold outside, and it congeals with the oil to form this gunky whitish looking stuff. It clogs the breather hoses and causes overflowing to happen.

The way to avoid this "mayonnaise" is to run the bike long enough for it to get hot enough to boil off this condensed water out of the oil and vent it out the breather hose. This usually takes 30-45 minutes of running to get it warmed up enough and get the water out.
Short runs to and from work that are only a few minutes are not long enough to solve this problem. So, you need to run the bike to full warm conditions regularly, or this mayonnaise will continue to be a problem.

Even if there is not mayonnaise, the late model Bullets with the engine breather on the top of the oil tank don't breathe very well, and this oil puking behavior is sometimes alleviated by reversing that breather hose to the catch-can that I described earlier in this reply.

[Vince]

     Ace of course is spot on. This is common, especially in winter due to condensation. Here is something else to check. The oil tank is separate from the engine. Sometimes when sitting  with the engine off the oil seeps from the tank to the engine. This is called "wet sumping". the crankcase now has too much oil for the volume and the excess is pumped out through the breather. This is exacerbated when one checks the oil, finds it low due to wet sumping, and adds more.
     To minimize this by bringing the piston to compression with the kick starter after you stop, and but checking the oil after a ride so you can tell if it did wet sump. In this case you can start it without adding oil, and a couple of minutes of idling will correct the issue. The bike will smoke for a little while.

[Bullet Whisperer]

I experienced one of the last 'iron' 350 Bullets doing exactly as you describe and in this instance it had blown the composite head gasket, internally by a very small amount between the cylinder spigot and the right rear barrel / head stud hole. Some compression was escaping down the stud hole and blowing into the crankcase, nothing was blowing out into the outside world. In this case, I noticed a loss of power and saw the oil dripping from the right tool box while at a junction, close to home.
 You might get lucky and fix it by tightening the head nuts, or you may need a new head gasket to fix it.
 B.W.

[Spitting Bull]

Another important cause of oil blowing out through the breather and into the air filter box is putting too much oil into the engine in the first place.  More oil than necessary will take up more space than necessary  and will take longer to get to a useful temperature to help boil off any water emusified in the oil.  (With too much oil plus short runs in cold weather, this may never happen at all). The best oil-level is just below the midpoint between the "full" and "empty" marks on the disptick. 

Good riding!

Tom

[Blltrdr]

I experienced one of the last 'iron' 350 Bullets doing exactly as you describe and in this instance it had blown the composite head gasket, internally by a very small amount between the cylinder spigot and the right rear barrel / head stud hole. Some compression was escaping down the stud hole and blowing into the crankcase, nothing was blowing out into the outside world. In this case, I noticed a loss of power and saw the oil dripping from the right tool box while at a junction, close to home.
 You might get lucky and fix it by tightening the head nuts, or you may need a new head gasket to fix it.
 B.W.

I would say your analysis is off target. I think the last post by Spitting Bull is very valid along with Ace's suggestion. The only thing to add is to check the drain hose to the timing cover which is likely clogged, allowing the can to overfill. I think it was Pete Snidal that suggested putting an inline petcock on that drain line and plugging the nipple off of the timing case. If you do something like Pete suggests you would have to open the petcock on schedule so you don't overfill the can. A complete removal of the system and rerouting the duckbill from the catch can to the rear of the bike is the best fix that has been done by many members.

[ace.cafe]

All the things mentioned on this thread are potential causes, so it might be best to work your way from the easiest fix to the hardest fix, and see where it ends up fixing the problem.
 

[Chuck D]

Any help would be appreciated.  Yesterday went for a ride and I got about 30 miles into it when I noticed oil pouring out of the air filter box.  There were no other issues with the bike.  I know that the breather tube vents to the air filter, and ALL the oil was pushed out through the breather tube.  Luckily I noticed it at a stop sign, shut down the bike and trailered it home.  So I'm pretty sure there's no damage due to oil starvation.  Now I'm just guessing here but it seems that either the oil pump failed or the oil return line is clogged.  Are there any other possibilities?  Also, how do I go about troubleshooting this problem?  Is there an easy way to determine which it could be.  I'm not a mechanic, but I have the next best thing... a friend who is fairly competent with bikes.

UniqueGirl,
This is a VERY common problem with these bikes and one that most of us ironbarrelers (myself included) have dealt with. It kinda freaks you out the first time it happens but at the same time offers a nice opportunity to dig in to the bike a little and get your hands dirty in a non invasive sort of way.
As it happens, the finest minds on this forum (I'm not kidding) have weighed in on this and I can't add much that hasn't been covered. So read the posts carefully (especially Ace's and Vince's) and then check it out on your bike and I'm sure it will make complete sense to you. Have fun!
Chuck.

[Bullet Whisperer]

I would say your analysis is off target. I think the last post by Spitting Bull is very valid along with Ace's suggestion. The only thing to add is to check the drain hose to the timing cover which is likely clogged, allowing the can to overfill. I think it was Pete Snidal that suggested putting an inline petcock on that drain line and plugging the nipple off of the timing case. If you do something like Pete suggests you would have to open the petcock on schedule so you don't overfill the can. A complete removal of the system and rerouting the duckbill from the catch can to the rear of the bike is the best fix that has been done by many members.

It may well turn out that I am 'off target' in this case, but I thought it worth mentioning my experience, as the symptoms are the same and a new head gasket fixed the machine I refer to. As has been said, 'Any help would be appreciated'.
 B.W.

[ace.cafe]

I too, have seen a blown head gasket causing high crankcase pressure, which can cause these kinds of problems.

It is good to get as many potential causes out on the table as possible.

[RGT]

one thing you may also want to do is maintain the oil level a little below the line marked on the dipstick, many have found that by maintaining the oil level at 1/2"+/- below the full line with engine/oil hot helps reduce oil consumption/breather loss and wet sumping

[Blltrdr]

It may well turn out that I am 'off target' in this case, but I thought it worth mentioning my experience, as the symptoms are the same and a new head gasket fixed the machine I refer to. As has been said, 'Any help would be appreciated'.
 B.W.

Of course your help is appreciated. I think throwing a possible blown head gasket in the mix before a confirmation that the obvious causes don't seem to be the problem can add a little stress to a new owner. I'm betting on the simple fix to make things right for her.

[UniqueGirl]

I appreciate all the advice. I will have my friend read your co ments and we willntry to work through this. I can't wait to fix it and ride again. Be safe and thanks again. Unique girl