Little oil leak...

[gstallons]

Well , I did say I didn't care for it ! I will have to look at it again to make sure , but I think it is  made that way . All my manuals are out in the shop.

[gstallons]

I had to go look. Yes , it is that stupid . It should be vented to the atmosphere but it isn't . I know there is a screen in the return hose to keep debris out of the crankcase .

[activpop]

Great, no rust, just water. 

[gstallons]

NOPE . I am wrong . there is a fitting and hose at the top of the frame (visible) at the front of the fuel tank and goes back to the air cleaner housing that vents to the inside of the housing. This keeps crankcase pressure from building up and ruining things . My apologies for the heresy.

[activpop]

@gstallons, take another look. On my two Sports in the shop the rubber breather hose connects from the upper rear of the engine to the underside of the spine frame at the front of the tank location. The metal braided tube at the rear of the sump land on the side of the spine approx mid tank. Pg 75 of the parts catalog shows this. Check it out and let me know what you think.

[activpop]

Hence my previous concern about a risk of contaminating the oil. It seems like it is a closed loop system, where the give and take changes in pressure take place in a rectangular steel tube. Am I seeing this right?

[docc]

16 minutes ago, activpop said:

@gstallons, take another look. On my two Sports in the shop the rubber breather hose connects from the upper rear of the engine to the underside of the spine frame at the front of the tank location. The metal braided tube at the rear of the sump land on the side of the spine approx mid tank. Pg 75 of the parts catalog shows this. Check it out and let me know what you think.

This is correct, crankcase ventilation/oil vapor travel up from the back of the engine through the nefarious double-bend rubber hose under the frame to the bottom of the frame spine behind the headstock. The frame cavity acts as a separator with the gaseous fraction following the path @gstallons describes (a hose visible from the fitting on top of the frame spine, behind the headstock/ in front of the tank) to the airbox, and the liquid fraction draining down through the frame cavity to the return line and back into the sump.

Ideally, adequate running temperatures will evaporate the water before it drains back into the sump. Less than ideal would be short operating times, very wet environs, and long storage periods.

Also, oil selection plays a part. Pure synthetics (true ester base oils) have close to zero evaporation loss from heat and aid the efficiency of a complex, closed loop, crankcase ventilation system like ours.

[docc]

One of the difficulties assessing the system is that the vapor recovery (which would include water vapor) is not on the parts diagram for the ventilation system ("oil pump"), but on the "air filter" page (16-20) . . .

[activpop]

Interesting. So it is not truly a closed system, it has an open line to the airbox. So when the engine is running, especially at higher rpms, there is negative pressure pulling out of the spine. So I'm not sure if that helps or hurts this condition of possibly getting oil contaminated, simply because there is an oil line open to the spine. Does oil ever get pulled up there? IDK. I'm no engineer.  All this looking around though has me finding a crack in the rubber tube coming up from the engine. Time to visit the old thread on replacing it.  How many tubes have you replaced on your high mileage Sport @docc?

[docc]

 

I've only replaced my vent hose once, but it really wasn't the source of my leak problems. Part of my issues was the #15 gasket for the oil pipe that the hose attaches to. (Notably, oil leak from this gasket appears at the 'weep hole" at the bottom of the clutch housing.)

[docc]

@activpop, was your leak at the washer, #20, in that diagram?

[activpop]

Sure was. Dry as a bone now.

[audiomick]

2 hours ago, activpop said:

Interesting. So it is not truly a closed system, it has an open line to the airbox. ...

It would be a bit pointless if it were a closed system. It is there to compensate for the change in volume in the crankcase as the pistons go up and down. This change in volume is not all that far short of the displacement of the engine. A closed system would increase the total crankcase volume, thereby reducing the relative change in volume, but would not be able to compensate for the change. For that, air has to be able to escape on the downstroke, and get back in on the upstroke.

[activpop]

@audiomickI'm very clear on why the pressure needs to be handled, just don't understand why a line that is connected directly to the sump has to be part of it. My older Ducatis just had a black rubber hose that came from the top of the crankcase and was strapped to the frame under the seat.  Maybe that system is ancient now, but it worked very simply. Why the oil line is part of this system now is what I question. I'll stop beating a dead horse.

[audiomick]

2 minutes ago, activpop said:

I just don't understand why a line that is connected directly to the sump has to be part of it. ...

Book it up to environmental protection. The air that comes out of the crankcase is heavy with oil vapour. It's better for the environment if the re-condensed oil goes back into the motor.