Smoking and oil in airbox

[MotoX]

So I picked up my 97 Valkyrie this spring with about 89,000 miles and after riding back and forth to work and putting about 2500 miles on the bike, I was riding home and had been cruising at around 70 mph for a few miles when suddenly the bike started smoking out both tail pipes.
I pulled over and examined the bike. Nothing sounded or looked out of place so I decided to attempt riding it home.
I did take it easy but nothing felt different power wise and everything seemed normal besides the smoke.
After getting it home I had burned almost a quart of oil in 15 miles and before that I never had any oil burning.
I found the source of the oil is coming from the crankcase breather. It sprays into the airbox and then is run thru the engine. I pulled the breather, cleaned it and the airbox.
I then test rode it and it was like normal for a bit until once again the breather filled with oil and began filling the airbox.
I pulled plugs and nothing looked off. Compression all was even and near 150. A scope down each cylinder showed clean cylinder walls with nice cross hatching and no extreme carbon build up.
There is no oil in the coolant or vise versa and I have changed the oil. I'm kinda stuck on which direction to go next. I thought the breather would have a sort of valve, like a pcv valve and that was failing but I'm not finding anything like that. Any help would be appreciated!

[Chrisj CMA]

When you changed the oil, how much did you put in?

I won’t mention any names but it has happened that someone thought the big jug was 4 quarts but in fact it was five.

Overfilling could possibly explain that. I have no other ideas

[The emperor has no clothes]

A couple things to check. Is your dragon drool tube so full that it's backing up ? Is the crankcase breather catchment container in place ? Possibly a previous owner removed it erroneously during a desmog. Are all the breather hoses unkinked ?

[Valker]

Is the clutch working normally?

[MotoX]

So clutch works fine, no issues there.

The original smoking happened about 2,000 miles after the last oil change. I changed it again while checking things and no it's not overfilled...I quadruple checked because I know that's a cause of this issue.

That breather drain hose I did clean out. It was full of oil and after cleaning it, my next ride it was good until it filled it back up and started smoking again... All in about five miles of riding.

[Daniel Meyer]

If you're getting gas in the oil (bad float and possibly petcock letting it get there while sitting), gas/oil mix will foam and get in the breather...you also risk hydrolock.

You've changed it (oil) again? Did it do the deed after that?

[MotoX]

I don't think it's gas in the oil, mostly because I tried to smell for gas when I changed it and the oil level wasn't up, it was in the normal range and a bit low after it started smoking.

I haven't rode it since the oil change because I've been looking for the issue but might be worth a short ride just to see.

[WintrSol]

Sounds like time for a compression test, to me. 

[Bighead]

Sounds like time for a compression test, to me. 

Read his OP said it was done.

[WintrSol]

Sounds like time for a compression test, to me. 

Read his OP said it was done.

Oh, yeah, oops!. If that 150 is with a warm engine with throttles open, though, it is really low. Something is pressurizing the crankcase, and blow-by is the #1 suspect.

[MotoX]

I agree that it seemed a little low but here is my line of thought.
This problem was sudden. The bike never smoked until all of a sudden both pipes were spewing a lot of smoke from oil burning.
My original thought was broken ring but all of the cylinders are within 6 psi of each other. If a ring broke, one cylinder should show a significant drop. All cylinders might be low but it wouldn't cause this sudden of a problem. That's my opinion at least. Obviously I haven't solved the problem so I could be wrong.

[WintrSol]

Well, the scavenge oil pump is at the back, but without taking an engine apart, I can't see how it could be spraying oil into the breather. Maybe if the pressure relief valve on the main oil pump sticks closed, it could be involved in sending oil through the breather. Either one requires disassembly, just to find out. I can't think of anything else that can pressurize the breather, though, if not excessive blow-by. And to come on quickly like that, all six pistons/ring sets would have to go at once, given the pressure readings. We appear to need someone who is regularly inside these engines to opine.

[Paladin528]

overservicing will cause the oil to siphon into the breather.  This will give you a puddle of oil eventually in the Airbox but a Quart would be readily visible by pulling the plug on the drool tube.
Overservicing can also in rare cases blow one of the seals.  I am not sure which one and if this would be the result.

[gordonv]

MotoX, I have a question for you.

How do you check the oil level?

You need to stand the bike up, remove the dip stick, wipe, and place it back into the hole, do not screw in. Then remove and check level.

I know you mentioned this happened 2K after the oil change, but is either an FYI for others, or might be why you show correct level of oil but have too much.

[..]

When you changed the oil, how much did you put in?

I won’t mention any names but it has happened that someone thought the big jug was 4 quarts but in fact it was five.

Overfilling could possibly explain that. I have no other ideas

Ahem!

[MotoX]

So I thought I possibly fixed the problem by going to a simple breather filter vs the original breather into the air box. It ran great all spring and early summer but then it suddenly decided to blow oil again.
Basically, as far as I can tell it's that the crankcase is pressuring up. Wondering at any ideas. Kinda debating on the oil system being the candidate but thought I'd run it passed the forum first. Any suggestions would be great.
Oh and I know it's not over filled on oil.

[da prez]

  Just a crap shoot. What kind of oil. It needs to be spec"d for the bike.

                                                        da prez

[97BLKVALK]

After reading through the thread I did not see if your Valk was desmogged.

Is your Valk a 49 state or california model?

Michael

[Madmike]

Service manual (aftermarket Clymer) mentions removing and cleaning two hoses along with removing  a plug and intermittent drain routine which needs to be more frequent if run hard or in rain.  Have you checked the hoses for the vent system to make sure they are not restricted by gunk or degradation (perhaps a "flapper" that acts like a check valve at times)  

Are you making oil??  My experience is that this sort of thing is usually an end result of either high oil level or high crankcase pressure so things that are related to creating these situations  would be my shot at solving the issue.

[MotoX]

So those hoses were removed when I changed from the factory vent to a breather filter so that's not my issue.
I haven't desmogged my bike yet but I'm impatiently waiting for the shiny kits from redeye to come back in stock because I basically have the system removed at this point and would rather leave it off.
Oil level was at the full mark before my rides and with the current situation, it dumps enough oil to be off the dipstick but not enough to kick on the low oil pressure light. So I'm not making oil or over filled, it dumps oil. Both times I caught it only a couple miles from home so I limped it home and added oil.

[John Schmidt]

Might consider removing your aftermarket breather and use the OEM system. You say it ran fine for some time, probably long enough for the non-OEM breather to get saturated and partially/totally plugged.

[Willow]

So those hoses were removed when I changed from the factory vent to a breather filter so that's not my issue.  ...

I'm not certain that's the right answer.  One of those hoses drains from the breather.  It is a length of hose that partially fills up with oily residue.  We refer to it as dragon drool when we drain it.  Without the hose to collect that stuff it will accumulate in the breather.

[Pluggy]

Might consider removing your aftermarket breather and use the OEM system. You say it ran fine for some time, probably long enough for the non-OEM breather to get saturated and partially/totally plugged.

Yes.  You know that concept from working on large aircraft.  Work is performed on the aircraft, and soon after something no longer works as expected.  Investigation starts with the last work performed.  Put things back to the way they were prior to that work, and the failure often goes away.   Same holds true for motorcycles.

[Pluggy]

So those hoses were removed when I changed from the factory vent to a breather filter so that's not my issue.  ...

I'm not certain that's the right answer.  One of those hoses drains from the breather.  It is a length of hose that partially fills up with oily residue.  We refer to it as dragon drool when we drain it.  Without the hose to collect that stuff it will accumulate in the breather.

Thanks for bringing that up.  One upon a time, I didn't recognize the term dragon drool tube.  Turned out to be the air box drain tube and fitting like on my 1980 Honda.  Neither bike accumulates much moisture there, but it is easy to check.

[Madmike]

Going through the emmissions sections in the manual it doesn't seem that there is anywhere that there are "external" sources of any air that would be at high pressure back in to the base.   In the troubleshooting section high base pressure goes back to  leaking compression air or a blocked breather system.

From your posts, it seems like it is when the oil gets hot that the problem occurs.  Some of this may be already covered but to ensure it hasn't been overlooked......... these are the things that occur to me.

Did you add or change oil at any point just before first occurrence of the problem??

What weight and type of oil are you using??  Energy-saving oil can cause slippage in trans, slippage leads to oil heating more, heat causes expansion.  If the oil itself is expanding to the point that it covers the bottom of the breather tube then otherwise "normal" base pressure may blow it out and into the breather system.  With internal passages it may be that the system purges a quart of oil before it clears itself.

Are you using an OEM or aftermarket dipstick??  Is the dipstick full mark in the correct place??  I have an aftermarket dipstick with a chrome handle, from the bottom of the threads to the full mark is 8".

Are you checking the level with the engine "warm", oil settled, bike in an upright position (not on sidestand) and dipstick dropped in (not screwed down). 

Wondering if you get the same problem if you lower your oil level a bit - maybe carry a quart of oil so you have some if it dumps.

[MotoX]

So before I changed the breather to an aftermarket filter, I did clean that hose and the breather twice and still had the same issue. That’s when I thought I’d try the aftermarket filter so the problem isn’t the filter or factory breather. Same issue with both options.
Dipstick is factory and I’ve checked it warm and cold although I do typically screw in the dipstick when checking but if that did anything it would actually lower my oil level. And yes I’m level, not on the kickstand.
I am running 5W-20 full synthetic oil so could that be the issue?

[Madmike]

So before I changed the breather to an aftermarket filter, I did clean that hose and the breather twice and still had the same issue. That’s when I thought I’d try the aftermarket filter so the problem isn’t the filter or factory breather. Same issue with both options.
Dipstick is factory and I’ve checked it warm and cold although I do typically screw in the dipstick when checking but if that did anything it would actually lower my oil level. And yes I’m level, not on the kickstand.
I am running 5W-20 full synthetic oil so could that be the issue?

The oil recommendation for multigrade starts at 10W at 10 F, for a 10W30 or 10W40 oil.  The 5W20 will be lighter (watery) at the higher temperatures and will only get worse with use.  Personally I would not be inclined to use it.

I have always understood that the energy conserving oils have friction modifiers in the additive package that can cause transmission slippage and so should be avoided.

You are correct about the dipstick being screwed in giving you a lower full level.

Is there an operators manual in the battery box??  That should have the recommended oil chart in it.

You may notice quieter and smoother operation with a less viscous oil.  You can likely find pages full of discussion on "Rotella T" and "Mobil 1" through the search function, they were pretty popular topics about 10 years ago.

Here is a link to an old oil discussion, keep in mind that the more range between the cold and hot numbers the more likelihood of "shear".  Here is a link to that with explanation.  https://www.pistonheads.com/gassing/topic.asp?t=163352&f=66&h=0

Bob the oil guy site also has lots of explanations on oil.

[John Schmidt]

When you screw the dipstick in for an oil level reading, it will read higher on the dipstick and will be inaccurate. I don't believe if it reads higher on the dipstick that relates to a lower full reading....just the opposite. Just do it correctly to find out what the actual level is....pull it out, wipe it off, then insert without screwing it in and done with the bike level. If the motor is cool it will give a slightly higher reading since the oil has had a chance to flow/drip back down into the lower case.

[Daniel Meyer]

This can also happen if you are getting fuel in your oil (from a bad carb float or down the #6 vacuum line to OEM petcock). Some gas gets in cylinder, makes it through the rings (instead of hydrolock) into the oil, oil foams when running/hot till fuel is gone.

[klb]

Reading about your problem here I searched the web and
found several post about running 5w20 oil in a motorcycle
and getting oil in the breather box. After swapping to 10w40
all said no more problem.

[SCain]

Wow, lots of good advise and knowledge to follow here, i remember years ago I had over oiled my K&N air filter, the filter was so restricted it was pulling the oil from the filter and I believe it may have pulled the vapors from the crankcase breather. I remember it smoking a little, just wanted to share this and make sure your aircleaner is clear 

[Firefight100]

You should probably do a cylinder leak down test.  A compression test will not always disclose a broken or worn ring.  Especially if there is extra oil in the cylinder to seal the defect.  A leak down test will show the defect, if it is in the cylinder. 
Search youtube for demos of test.    Here is a motorcycle test  https://www.youtube.com/watch?v=CC1EZCxDnLc

[old2soon]

    And my 2 cents and may not be worth that much. I run Mobil 1 full synthetic 15-50 year round.
            NO/NONE/NADA oil issues with this oil. When I got my 06 Pancho I was a bit surprised it called for 5-30 full synthetic. Personally I think 5-20 a tad light fer these machines. But I also Know what goes along with opinions.  RIDE SAFE.

[MotoX]

Update!
So there was an issue with the vacuum activated valve between the reed valves in the smog system so I decided to desmog the bike. Didn’t see this as my primary issue but an issue I wanted to address.
I changed the oil to 10-30 and went for a ride. First note was the bike ran much smoother so I’ll be sticking with that but didn’t solve my problem.
I went for a ride and noticed a slight clutch slip once and made it about four miles before it once again began puking oil out the breather. So rode it home and let it cool before checking the oil. Somehow, I had more oil in it before I left (and I checked it 4 times before I left).
So I was a bit perplexed on how I gained oil. Only thing I could think of is some portion of oil was trapped when I drained and filled it. I had changed it cold this time so maybe that had something to do with it. I decided that I needed to look into the clutch slip and pulled the cover.
So the friction plates are wore bad. I bought the bike with 90k on the odometer and the clutch never changed over the last 5k so I’m curious how it’ll feel with a fresh clutch. But point is, the little strainer that allows oil to pass between the block and clutch area was blocked with small fibers from the clutch. So it was allowing oil in, not out and the breather is in that portion so with the clutch spinning and excess oil trapped, it would push oil out the breather.
So new clutch is ordered and I’m going to spend a bit of time cleaning things while I wait the week or two for parts and then try again!

[Madmike]

All is answered, interesting about the drain passage and screen to keep the clutch shrapnel out of the shared oil sump.

I would check across the steel plates with a straight edge for being flat  or you can lay out a piece of plate glass and a feeler blade if you don't have a surface plate as suggested in the service manual.  Rebuilt lots of Allison autos and power shift transmissions and we would check every plate as the heat from slipping can distort them, if they get "coned" the contact face area decreases which could be a problem.  Also it is good to actually submerge the frictions in fresh oil and let them soak for a while to pre-condition them.

[The emperor has no clothes]

Update!
So there was an issue with the vacuum activated valve between the reed valves in the smog system so I decided to desmog the bike. Didn’t see this as my primary issue but an issue I wanted to address.
I changed the oil to 10-30 and went for a ride. First note was the bike ran much smoother so I’ll be sticking with that but didn’t solve my problem.
I went for a ride and noticed a slight clutch slip once and made it about four miles before it once again began puking oil out the breather. So rode it home and let it cool before checking the oil. Somehow, I had more oil in it before I left (and I checked it 4 times before I left).
So I was a bit perplexed on how I gained oil. Only thing I could think of is some portion of oil was trapped when I drained and filled it. I had changed it cold this time so maybe that had something to do with it. I decided that I needed to look into the clutch slip and pulled the cover.
So the friction plates are wore bad. I bought the bike with 90k on the odometer and the clutch never changed over the last 5k so I’m curious how it’ll feel with a fresh clutch. But point is, the little strainer that allows oil to pass between the block and clutch area was blocked with small fibers from the clutch. So it was allowing oil in, not out and the breather is in that portion so with the clutch spinning and excess oil trapped, it would push oil out the breather.
So new clutch is ordered and I’m going to spend a bit of time cleaning things while I wait the week or two for parts and then try again!

I'm curious how you determined the clutch discs were worn ? You removed the clutch and took it apart ?

[MotoX]

Thanks for the tips MadMike! I’ll make sure to double check those plates tonight.

So I was snore to tell they were worn because I pulled it apart and even in the basket could see they were down to almost nothing.

[Madmike]

Thanks for the tips MadMike! I’ll make sure to double check those plates tonight.

So I was snore to tell they were worn because I pulled it apart and even in the basket could see they were down to almost nothing.

Do you have the manual??  Here is a link to a downloadable version, gives you a zip file that you can unzip and get a full PDF.

http://www.valkyrienorway.com/index.html

There is a minimum thickness on the frictions.  3.5MM I believe, also check for "flaking" at the grooves if you are going to reuse any of the fiber coated friction plates.