Crankcase Breather ??? Maybe not

[Stig / Major Tom]

Looking over the service schedule page in my LIKE200i Owner's Manual and came across this: the "Crankcase Breather" should be cleaned every 1200 miles....on schedule with engine oil changes and various other 'inspections'.
"Crankcase Breather" ?

Oh, yeah - the thing that the old motor-heads call the 'puke tube'!
(not sure how much this tube is 'breathing' - since it is capped)
Always see it when I'm changing the engine oil - so I remove the cap and drain the small amount of oily/water mix. This happens @ every 600 miles, and there is rarely much more than a few drops in there.




BTW - anyone ever see a dirty air filter in a LIKE200i ?
I bought 2 spares when I bought my scooter - I think my supply will last until the Rapture.
Stig

[TroutBum]

I have yet to have any measurable gunk in the puke tube. The same for the air filter. It's as clean as they day I installed it. I do replace, but I doubt it was needed other than for peace of mind.

[ole two wheels]

The puke tube, you referred to, on older engines, was a pipe on the crankcase, usually with some sort of wire mesh in it to catch the oily mist and then direct the crankcase pressure down toward the ground and vented to the atmosphere. Then the EPA got involved and said we could no longer relieve the pressure that way. Bad for the environment and all that jazz. So now the pressure is recirculated back through the engine via a rubber hose from the valve cover to the air intake of the carburetor so that it can be drawn into the combustion chamber and burned. Usually there is some sort of filter inside the valve cover to retain the oily mist, while relieving the crankcase pressure. There is also some sort of one-way valve, maybe reed valve, that only lets pressure out, but not back in. In this case it would necessitate the valve cover removal to gain access to the crankcase pressure relief filter. The auto industry has managed this with a PCV valve since the sixties. Hope this will give you some insight. It would seem to me that this filter should be cleaned or replaced at the same time that you  check and/or set the valve clearance.

Mac, aka "ole two wheels

[ole two wheels]

The tube that Stig posted the picture of is where that oily mist is collected from the filter in the valve cover. This is not the pressure relief hose. As such it will hardly ever have much to drain from it.
Thanks for allowing me to share.

Mac

[LidoCA]

That is where you add the antifreeze.

[Stig / Major Tom]

OK, the owner's manual says to clean a "Crankcase Breather".
But the only thing I see to drain and 'clean' is the "Airbox Drain Hose" from the airfilter box.
This capped tube is not breathing much, I don't think.



The service manual calls the black tube tube connected the the cylinder head cover a "Breather Hose"...and I am thinking that is this black hose? I found mine had come adrift from the clip alongside of the airbox drain.
 


Still, I wonder how that oil and moisture is getting into that tube from the airbox?
So the cylinder head cover breather is only venting, not draining?
No matter, I'll keep draining the one with the cap...and will trace the black hose & see if it does indeed go to the cylinder cover.
Maybe it goes to the charcoal canister?
Still learning stuff here.
Stig

[ole two wheels]

Stig, the thing inside the valve cover is called breather separator. the exit nipple and black hose then is routed to the intake side of the carburetor. Some motors have it in the air hose, from the air cleaner box, (after the air filter) directly into the carb. Others have the black hose  go into the air box itself, (before the air cleaner filter) If it connects to the air box, then there is a recess under the filter element to trap what ever oily mist gets pass the breather separator and that clear, plugged hose hanging down is where that oily miss collects The oily mist that does get separated inside the valve cover drains back into the crankcase. Yes there is a one-way valve coming out of the valve cover
I have a way of explaining things, that some times gets folks more confussed, but I hope, in this case, you can understand what I'm trying to say.

Mac

[LidoCA]

 I had the LX taken apart for the last week, while attempting to extract a broken bolt for the air box mount. (Ended up drilling out the bolt and tapping the threads, after breaking an easy out and a drill bit inside the bolt, but that is a different nightmare) I emptied quite a bit of oil from the puke tube. The air cleaner foam was soaked with oil in areas. I must have over filled the oil at some point. I will load pictures of the air cleaner and tube when I get the pictures worked out on this tablet.

[Stig / Major Tom]

I had the LX taken apart for the last week, while attempting to extract a broken bolt for the air box mount. (Ended up drilling out the bolt and tapping the threads, after breaking an easy out and a drill bit inside the bolt, but that is a different nightmare) I emptied quite a bit of oil from the puke tube. The air cleaner foam was soaked with oil in areas. I must have over filled the oil at some point. I will load pictures of the air cleaner and tube when I get the pictures worked out on this tablet.

Thanks Lido.....
Pix when possible.
Yep, I  usually find a tablespoon, or less, of stuff in that tube when I  do oil changes.....which I  do about every 600+ miles.
Posting from my fav seat on sidewalk in my coffee  village.
Super to be riding again. Light rain, 45 degrees. One heated glove quit today. Broken wire right at battery .....might be a bear to repair.
Stig

[CROSSBOLT]

Same for me on the puke tube for Yager and DT.

Karl