V11 Marking Its Spot (oil in the airbox)

[leroysch]

Noticed that the bike was doing something for the first time (17,700 miles)....marking its spot. Bike was on the sidestand..and the path (from the floor) goes up to the shift lever

to the LH side boot to the airbox.

It's oil....checked everything I had fiddled with recently (clutch bleeder, starter) and inspected about the lid to the airbox (fuel tank not off quite yet) with nothing else of note. Engine oil level (OEM stand) is low but in band. Checked my records and its been 7000 miles since I put a new one on (ooops). At this point my plan is to remove the fuel tank....replace the air filter and see if anything else jumps out at me. Anything else I should be checking while I'm in there?

[Scud]

Check the crankcase vent hose. I think that is the most likely culprit.

[gstallons]

You will probably find the return tube the culprit . It will be easy or a MF to change . The easiest and best purchase will be MG Cycle . When you install , make sure you clock the hose clamps where they will be easy to tighten .

[leroysch]

Appreciate the above places to look. 

Removed the tank and air box to get a better look at the situation. The breather pipe (goes from the bottom front of the spine to the top of the motor just aft of the Vee, right?) looks clean along its length and interfaces as does the return line from the side of the spine to the sump adjacent to the drain plug (right?). The only path I can make out is inside the airbox starting at the front where a tube enters with the trail leading into the cavernous depths on the LH side of said box. The airbox itself was reasonably clean and the filter wasn't oil fouled. I'm assuming that if either the crankcase vent or return line was the culprit, I'd be able to see evidence of their malfeasance somewhere along their runs.

Reading thru various forum threads my understanding of what's going on here is that the crankcase breather vents thru that big tube going to the bottom front of the spine where two subsequent paths: one to the airbox; the other thru the spine to the sump return line. Please correct my thinking if wrong.

At this point I'm going to check/compare the plugs....drop the sump...scope out the situation while doing a oil/filter change...and button her back up and keep an eye on things.

[docc]

19 minutes ago, leroysch said:

Appreciate the above places to look. 

Removed the tank and air box to get a better look at the situation. The breather pipe (goes from the bottom front of the spine to the top of the motor just aft of the Vee, right?) looks clean along its length and interfaces as does the return line from the side of the spine to the sump adjacent to the drain plug (right?). The only path I can make out is inside the airbox starting at the front where a tube enters with the trail leading into the cavernous depths on the LH side of said box. The airbox itself was reasonably clean and the filter wasn't oil fouled. I'm assuming that if either the crankcase vent or return line was the culprit, I'd be able to see evidence of their malfeasance somewhere along their runs.

Reading thru various forum threads my understanding of what's going on here is that the crankcase breather vents thru that big tube going to the bottom front of the spine where two subsequent paths: one to the airbox; the other thru the spine to the sump return line. Please correct my thinking if wrong.

At this point I'm going to check/compare the plugs....drop the sump...scope out the situation while doing a oil/filter change...and button her back up and keep an eye on things.

You are 1) right, 2) right, and 3) correct. That's three for three!  

These closed loop crankcase breathers are designed to separate the vapor portion (line to the airbox) from the liquid portion (frame spine through the return line to the sump).  Some work better than others and the V11 design is not very effective at the separation, IMO. As a result, too much oil (not just vapor) ends up through the airbox. You may find that the hose connections between the top-front of the frame spine and the airbox could be more snug. Or that line has degraded.

[Scud]

That is the right hose. But a leak can still be caused if that rear hose clamp is loose. What happens is the oil goes outside the metal fitting for the hose, down through the bell-housing and makes the type of mess that you have.

I would try to remove at least the rear fitting of that breather hose and inspect it for internal cracks. Maybe give a twist first to see if it is loose. I once forgot to tighten up that rear hose clamp and it made a mess.

[Lucky Phil]

He needs to remove the air filter and look INSIDE the airbox at the airbox floor, not just at the filter.

Ciao

[docc]

This is really interesting. My right side airbox boot is totally dry and my left is scuzzy with oily deposits and accumulation like @leroysch shows. Yet all of the "bell housing" area leaks, including the nefarious crankcase vent tube have been seen to on my Sport in the last couple years. Something is escaping us?

[Lucky Phil]

3 minutes ago, docc said:

This is really interesting. My right side airbox boot is totally dry and my left is scuzzy with oily deposits and accumulation like @leroysch shows. Yet all of the "bell housing" area leaks, including the nefarious crankcase vent tube have been seen to on my Sport in the last couple years. Something is escaping us?

Yes docc, your bike like many is breathing oil into the airbox and it ends up on the LHS because that's the side it leans on due to the LHS side stand.

Ciao

[docc]

Just now, Lucky Phil said:

Yes docc, your bike like many is breathing oil into the airbox and it ends up on the LHS because thats the side it leans on duel to the sidestand.

Ciao

My old tub may be breathing rather more oil into its airbox than most.

Yet, it is not on its sidestand very much, living rather languishingly above the footlights on her dais.

Still, that "vapor line" from the frame spine to the airbox connects to the left side? Am I recalling that correctly?

And it only pushes on? No clamps?

[leroysch]

13 minutes ago, Lucky Phil said:

He needs to remove the air filter and look INSIDE the airbox at the airbox floor, not just at the filter.

Ciao

"The only path I can make out is inside the airbox starting at the front where a tube enters with the trail leading into the cavernous depths on the LH side of said box."

Ummmmm....

[leroysch]

1 minute ago, docc said:

My old tub may be breathing rather more oil into its airbox than most.

Yet, it is not on its sidestand very much, living rather languishingly above the footlights on her dais.

Still, that "vapor line" from the frame spine to the airbox connects to the left side? Am I recalling that correctly?

And it only pushes on? No clamps?

Yeah..it's on the LH side...mine didn't have a clamp on it.

[docc]

Just now, leroysch said:

Yeah..it's on the LH side...mine didn't have a clamp on it.

Is it wet around the outside of it, or is all that oil coming from the crankcase venting and trying to get out from inside the airbox on the left side?

[docc]

With so many miles/kays on my Spiner, I wonder about what is inside that frame spine. If it is cloggy, maybe more of the oil portion is being forced to the airbox?

Perhaps, open the top front, release the return line from the sump, and flush the spine out with "something?"  I was thinking kerosene or mineral spirits, but maybe there are dedicated fluids for this task . .

[leroysch]

Dry outside....oil trail starts inside the airbox (at the front) where the tube enters. Oil trail exits the air box about the external grommet surrounding the LH boot. 

Just to see, I'll check the LH/RH boot inner surface and engine interface for residue comparison. 

9 minutes ago, docc said:

Is it wet around the outside of it, or is all that oil coming from the crankcase venting and trying to get out from inside the airbox on the left side?