The Harley slobber... oil leak from the air filter.

[Rod Stewart]

Dolt thanks for posting those pics. Very illustrative.
Another thought about internal recycle of breather gases that I don't think was mentioned above (though I might have missed it) is what effect this gas may have on plugging up the IAC ports and gumming up the IAC pintle lead screw in the throttle body. In another thread several folks have had to replace and/or clean the IAC with carb cleaner to get it to function, and life is not good when the IAC is not behaving, as I recently found out. Many reported noticeable volumes of black crud lodged in the ports. Logically the only place this crud could come from seems like oil/water vapors in the breather gases; unless it is possible that uncombusted fuel vapors rise back up through the throttle body after engine shutdown. Who knows?
Anyone have any thoughts on this scenario?
It seems to me like another point in favor of conversion to external venting.

 

[Jeff Klarich]

Gumming up and plugging of the IAC is a direct result of venting internally. Now that I vent externally my throttle body is clean as a whistle and have not had to clean IAC port.

 

[Rod Stewart]

Gumming up and plugging of the IAC is a direct result of venting internally. Now that I vent externally my throttle body is clean as a whistle and have not had to clean IAC port.

Good enough for me, thanks Jeff!
Now the only critical part would seem to just where to terminate the vent hose outlet, since it will drip an occasional oil drop or two, and you don't want that blowing back onto your rear wheel. Perhaps just beside the gas vapor vent hose that comes from the fuel tank? I don't think I will opt for the gas filter in the line as was discussed above, since oil molecules are way bigger than gas, and there may be a chance of it plugging up over time.
Thanks all for a great topic!

 

[Jeff Klarich]

Good enough for me, thanks Jeff!
Now the only critical part would seem to just where to terminate the vent hose outlet, since it will drip an occasional oil drop or two, and you don't want that blowing back onto your rear wheel. Perhaps just beside the gas vapor vent hose that comes from the fuel tank? I don't think I will opt for the gas filter in the line as was discussed above, since oil molecules are way bigger than gas, and there may be a chance of it plugging up over time.
Thanks all for a great topic!

I ran mine down by the rear brake pedal and lightly zip tied it as I followed the frame back just behind the foot board.
I don't use anything because mine never drips but will get moist to the touch at the end. I've seen some use a small lawn mower fuel filter at the end of the hose to catch anything that may collect.

I've never had a issue with blow back onto the tire or dripping so I never saw the need for any type of catch can or filter system.

 

[Bodeen]

I ran mine down between the primary and the trans. Zip ties it to the frame at the back of the primary. One word of caution, dont zip tie too tight. It will eject the oil dipstick at an impressive trajectory and distance, ask me how I know...........

 

[dolt]

Good enough for me, thanks Jeff!
Now the only critical part would seem to just where to terminate the vent hose outlet, since it will drip an occasional oil drop or two, and you don't want that blowing back onto your rear wheel. Perhaps just beside the gas vapor vent hose that comes from the fuel tank? I don't think I will opt for the gas filter in the line as was discussed above, since oil molecules are way bigger than gas, and there may be a chance of it plugging up over time.
Thanks all for a great topic!

Between the primary and trans is a good place; zip tied to the frame like Bodeen has done. The little clear inline gas filter will not plug up; it just acts as a baffle of sorts and if you ever see oil collecting there, you have more than typical crankcase blowby. Same goes for worrying about blowing back onto your rear wheel. It is a mist that is venting and while the mist is "wet" there shouldn't be enough wet stuff to worry about hitting the back wheel. If there is, like I said, bigger problems exist.

A catch can is more like belt and suspenders but if the motor is in good condition, a catch can shouldn't be necessary. Neither of my bikes leave drops on the floor but are wet to the touch as Jeff describes.

 

[Rod Stewart]

Here is another thought: What would be wrong with just running twin vent hoses overboard, and eliminate the T fitting? That would significantly reduce any back pressure, and just might eliminate launching your dipstick!
Rod

 

[Jeff Klarich]

You could run 2 hoses but why? Using a T and running 1 hose down makes a cleaner look.
As long as you don't collapse the hose when you zip tie it you won't have any back pressure issues.

 

[Bodeen]

You could run 2 hoses but why? Using a T and running 1 hose down makes a cleaner look.
As long as you don't collapse the hose when you zip tie it you won't have any back pressure issues.

Yeah one looks much better than two. With a much cleaner look.

 

[Rod Stewart]

I was wondering what kind of small inline fuel filters are available, so did a quick online search and came up with this:



Notwithstanding the somewhat odd supplier name, there is couple of things I like about these compared to small plastic fuel filters:
1. They are all metal construction, so no worries about heat meltdown.
2. Can be easily disassembled for inspection and cleaning.
3. The element is porous media, so it is robust, and it can be solvent cleaned, compressed air dried, and re-used.
4. Price is right, and free shipping to the US.
5. Light weight aluminum construction.

I ordered a couple just to try them out; the only colors currently available are red, bronze, and chrome.
I am thinking this could easily be mounted vertically just below/behind the AC backplate, with the inlet in the top and the outlet vent hose connected to the bottom. A T fitting to merge the two cylinder breather lines can be installed just above the unit. This location would make it easy to access and inspect as desired.
The body is 22 mm diam (~7/8"), and overall length is 72 mm (just under 3"), so the body length will be about 1-1/2" long. Hose connections are 1/4".
Just posting this info in case anyone else is interested
Rod