I saw that too.

And, I REALLY like that catch can. Hmmmmmm.....

 

I bought the same one. Here's what my catch can looks like installed.

 

I'm sure DK will chim in or would be very happy to correct any information if needed.

That said like others I choose to vent externally, no catch can. Numberous threads on how to do this mod can be found in the Dyna section if so interested.

 

I just bought one. $72 delivered from a kindly old gentleman on eBay lol. Found some black over stainless braided fuel line on Amazon.

How is reaching the drain plug where you have it mounted?

 

No problem. I use water pump pliers to get it off and start it with my fingers.

 

Found the thread. If you believe it's direct quote from DK Customs, then we have another vote for the "it drains back in the motor". See post 3

https://www.hdforums.com/forum/gener...breathers.html

DK says "Here's how the Outlaw Breather Bolts work on a typical bike- the hot oily air hits the first fine mesh screen and breaks up the oil, then it hits the foam filter. The air passes thru and most of the oil gets absorbed by the filter, then drops down to the little reservoir and goes back into the head. The oil that makes it thru the filter hits the outer fine mesh and is broken up into a very fine mist."

And also: "Every-time you put the bike on it's kickstand gravity will drop the oil out of the filter & reservoir and back into the engine"

So now we have an industry leader saying the oil WILL drain back into the motor. WTH?

 

I am not believing this is so difficult to understand. Once the oil mist passes the head breathers under the rocker support plate, it cannot return. The mesh in the OEM head breathers is intended to catch the oil which can drain back into the motor via the drain port in the rocker support plate. However, in the case of the Outlaw breathers, the oil that is captured in the foam can drain back into the motor when the bike is no the kickstand but it cannot drain back past the umbrella valve in the OEM head breather and will get pushed back into the Outlaw breather foam the next time the motor is fired up. Additionally, the amount of oil we are talking about is almost not measurable. I have nearly 10K miles on my built motor, which also as a bit of blow by on the rear cylinder, and have opened the drain on my catch can twice; guess what, nary a drop fell out.

This is not rocket science guys and DK Customs is correct in their advertising. You must also remember that there is a big difference between Outlaw breathers and plumbed system with a catch can like those installed by GibT and rgr357.

 

I guess I'm just plain stupid. Here's my problem. You and others say that no oil gets back in the motor once expelled from the breather. So much so that oil can potentially gather and pool in any upward directed hoses, etc. Then DK says "Every-time you put the bike on it's kickstand gravity will drop the oil out of the filter & reservoir and back into the engine" now I may not be the swiftest man, but drop back into the engine means it goes back into the engine... I don't know how else to interpret that? I'm not trying to be dense, difficult, or a pain in the ***, really.

 

OK, now we are splitting hairs. The point of confusion appears to be "oil draining back into the motor"; you may not be stupid but just don't understand how oil circulates through them motor and the function of the breathers.

All oil is returned from the top end back down to the crank case where the oil is picked up by the scavenge side of the oil pump and returned to the oil pan. The head breather function is to vent crank case pressure generated by the down stroke of the piston. So, what is being vented is a mixture of oil vapor, whatever condensate may be present and any uncombusted fuel; a corrosive mix of pollutant that the MoCo vents back into the intake to meet emissions standards.

Without getting into the weeds, the head breather sit in the baffle compartment in the rocker support plate. The oil vapor is pushed up past the umbrella valve, which is a one way valve, through the filter gauze which is intended to catch the oil which will gravity drain back into the system. The vapor however, once past the umbrella valve which is now sealed by the reverse of the air flow, passes into a passage way in the cylinder head before exiting through the external breather system which routes the vapor back into the intake or to an external venting system.

So, the only place "in the motor" any oil (remember, not really a measurable quantity under normal conditions) is between the external breather and the passage in the cylinder head. As long as the motor is operating, no oil or vapor will remain in this passage. However, in the case of Outlaw or similar breather, when the bike is on the kick stand, if any oil has collected in the foam element, it can drain back into the exit passage in the cylinder head until the next time the motor is fired up.

If there is an external "plumbing" system to vent the vapor and there are lines that run "uphill", any oil that has dropped out of the vapor can collect in the lines routed up hill from the external head breather port/bolts and drain back into the passage way in the cylinder head.

If there is an external "plumbing" system to vent the vapor and the lines run "downhill" to a filter, catch can or to the atmosphere, any oil that has dropped out of the vapor will collect in the filter, catch can or drip at the end of the exit line.

There are crank vents that are one way vents that can be attached directly at the external head breather port that could prevent any oil from draining back past the crank vent if the external plumbing routes the vent lines uphill.

The main take away from all this is that we are talking about such a small amount of oil that it is hardly worth the discussion and any oil that did collect in the cylinder head passage way past the umbrella valve should be viewed as in the venting system and not "in the motor"; it is just being held temporarily in the passage way until the next piston down stroke.

Anyone that doesn't understand how the oil circulates through the TC motor, how the two stage oil pump works and how the breather system works should read the Engine Oil Flow section of their service manual.

 

Ok, I think I actually understand now. So "drains back into the motor" should read "drains back into the motor only to get pushed out the next time it starts"...

I looked at some diagrams and see that passageway coming from the umbrella valve and baffles leading to the breather port on the head. I also saw the single oil drain next to the exhaust valve spring. There is indeed no way oil is getting from the vent to the drain back down to the bottom. So I was thinking of using one of those horseshoe looking breather vents (this: https://www.denniskirk.com/H30016.sk...ad=45713335117) that go up from the front cyl across to the rear cyl and down and out to a nipple but I don't like the thought of oil pooling in the front breather (the one going up). Unless the amount of vented gas is sufficient to blow it up and over to the other side? You think?

Sorry for the amount of time it took to beat this into my thick skull...