Recently I was asked by Papa_J to make a write up on how i made my CrankCase Breather. Feel free to hit me up with any questions you have.

So a couple of months ago, i made a set of crank case breather bolts using Mreed's Write up (https://www.hdforums.com/forum/sport...-breather.html)

I was getting a good amount of oil spray on my tins, so i decided to try this out.

This setup, does not stop the oil spray but it did reduce it a significant amount. Also this is by no means cheaper than buying a breather kit. This is just a different route.

Here is a list of what you will need. I bought everything from www.Mcmaster.com just search the part numbers on the Mcmaster website. This is exactly what i used, but as you use the website feel free to search for different finishes or colors, as long as you use all the same dimension parts you will be fine.


1. You will need 2 - 1" Long 1/2-13 Bolt (This one has a Black Finish to it) Part#94967A622
You will have to drill and Tap these bolts with 1/8 NPT Tap

2. You will need 2 Push-to-connect Tube Fitting, Swvl 90 Deg Elbow For 1/4" Tube Od X 1/8"nptf Mal
Part#51915K31

3. 1 ft of 1/4 Black Nylon Tubing
Part#5112K53

4.Push-to-connect Tube Fitting, Swivel Branch Tee For 1/4" Tube Od X 1/8"nptf Mal
Part#51915K71

5. Breather Vent, 1/8 Npt Female, 26 Max Scfm, 5/8" Height
Part#9833K24

I am sorry this isn't a detailed write up with step by step photos, i did this a while ago, it is very straight forward. Once you get everything just ut it together as it is show in the picture above. Please feel free to contact me if you have any questions.

 

Thanx for posting it.

 

Looks really cool!

 

way cool!!
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Nice!!!!

 

Flatiron - Excellent doc! Very clear, thanks. And a nice build, too.

Here's something to consider...

Compare the function of the stock breather to the home-builts.

Stock - the breather bolts have a very small ID, approximately the size of straight pin, plumbed into the air breather. That tiny hole reduces the suction, so full throttle won't suck up your oil supply. The downside is that whatever oil & gassses are ingested reduce performance because they are not a stoichiometric fuel/air mixture. Harley's engineers think this is an acceptable loss. Others do not.

Homebuilt - the breather is much larger ID (Flatirons is 1/4", some are more) but, while not subject to intake suction, are still subject to some degree of suction, when moving, due to airflow. The downside seems to be some oil spill.

Maybe the solution is to hide the outlet from the airstream and/or add a container to collect the oil?

 

I totally agree with you Howler. I was thinking about putting a small catch can. I have one that I used with my race car. Just trying to decide if I want to add the clutter to the bike. Trying to keep it as simple as I can. Also te only time it sprays oil is when I at on the highway, anything over 50 for long distance, and it sprays.

 

Old idea, less clutter...



Just keep it away from the rear tire