How-To: Crank Case Breather Mod (with pics)

[spazz8448]

looks good

 

[davidws]

Here's mine

I did the breather re-route last year, and this weekend I replaced my setup with this
CNC catch can (+threaded hoses from ebay, £21 shipped from Thailand)... you wouldn't believe the amount of mayo inside the old pipes... so glad that crap is not in my engine any more

 

[Jonny5zaliv]

I'm running straight pipe after the breather filter, everything's downhill, and it's been at least 10 days since install, but nothing's coming out of the pipe! Is that typical without adding a catch can?

 

[Jonny5zaliv]

Oh yeah, there is a drain cock at the end that stays closed until I open it, for the record.

 

[snrusnak]

^sometimes you get more gunk sometimes you get less gunk. Sometimes you get no gunk. There's many factors...

 

[SMUURF]

Thank you for this thread.

 

[KC_Buell]

I picked up a cheap compressor air filter" from Harbor Freight for my catcher then painted to match my color scheme

 

[Honzik8719]

Here is my breather mod

 

[BuellyBagger]

neone ever notice a lil smoke comin from the breather filter when idling after a ride? Went about 40miles hard riding and came home let it idle in the driveway for a minute and noticed a little smoke (it actually seemed more like steam than smoke) coming from the filter.

 

[CrazyTexan]

Ive read that people have noticed smoke comming from the filter. I personally never have, But I dont have my line plugged or a can, Just open vent.

 

[Frozone]

Ok, so I've read through the entire thread, and I'm stuck on one thing...

I just went to Home Depot and bought one of those really cool Air Line Filters. They had 1/4" and 3/8", but the 3/8" canister was like 6" tall!!!

I ended up buying the 1/4" cause the YouTube video I first saw had the same canister. So my question is this...

Do I have to run 3/8" tubing? Can I just run 1/4" line back to the filter and breather? If I have to run 3/8" for some reason, can I use a 3/8" to 1/4" reducer to go into the filter?

 

[snrusnak]

It will restrict it a bit. Not sure if it will be enough to cause an issue. If it's too restrictive it can cause excess crankcase pressure.

 

[Frozone]

Crap... Anyone else running a 1/4" Air Line Filter?

 

[ConVICK Pitbull]

Had to redo mine. For some reason FUEL line is NOT the same as oil cooler line, its more rigid. So went to a brass and hose company and got silicone air hose that has a heat rating 1.5x higher than the last fuel line hose and is way more flexible. In my add you can see it.

http://atlanta.craigslist.org/nat/mcy/3044062596.html

 

[BuellyBagger]

 

[Frozone]

Ok, so I hope this is the last time I have to ask questions before doing this mod. I'm getting ready to do it, but I've read where if you use an Air Line Filter (Catch Can), place it before the little air filter. I see some people who aren't doing that though...

My Air Line Filter is also 1/4" in... not 3/8", and some seemed to think it might cause excess pressure in the crank case. Therefore:

1. Should I place my 3/8" K&N air filter before my catch can and call it a day?

or

2. Still place the catch can before the K&N and not worry about it...?

Here's a picture of what I've got...

Also, I've read everything, but I'm having trouble discerning which hose to cut (it might be more noticeable if I'd actually pull the air box off, but I'm not there yet...). Can someone put a red arrow or give me a better idea of what hose needs T'd into?

 

[BuellyBagger]

depends if ur going out the front or the rear of the frame as far as where to cut. U'll be able to tell when u get in there (its pretty straight foward). I would put the filter b4 the catch can to release the crankcase pressure and the catch can to get the leftovers. i just used a a rad. drain after my filter, and still havent ever got nething to drain out of it. IMO the catch can isnt totally nescassary.

 

[jlrenken]

Idk I just let mine drain out the left side of the bike. No filter just a straight hose with a T that Ts into the crank case and out the back. I never see anything. maybe a drip hangin from it once and awhile.

 

[Frozone]

Alright, so I can finally add my name to the list of those who've done this mod. I've put maybe 2 miles on it since I ran the new line, but just connected it to the catch can this morning. I did notice a drip of oily fluid coming from the new 3/8" line.

Here's a picture of my completed job.

-Custom made bracket to hold the Air Line Filter. I ended up using a rubber lined clamp (like whats already mounted on that black bar that runs horizontal beside the engine), made my own bracket out of a 1" wide sheet of steel (2" tall, then bends 90 degrees and comes out 1" ). I also removed the filter thinking it might allow a little more air flow (since some seem to think the 1/4" in/out on the air line filter might restrict).

I know some seemed to think the 1/4" air line filter might not allow the crank case to breathe right and might build up too much pressure, but is there really that much pressure being exerted down these lines? It's more for venting, right? I made a custom setup so the filter could be before the catch can, but it took up an insane amount of space. I like minimalistic things... Anyways, enough babble here's a picture.

*The "Husky" logo will come off when I get home to some Goo-Gone
**And ignore the dinged up primary cover... The new one is being powder coated

 

[snrusnak]

is there really that much pressure being exerted down these lines? It's more for venting, right?

Yes and yes. People don't realize that pressure builds inside engines. If you were to plug up the breathers completely you'd start having oil leaks(gasket would blow out at the weakest point) almost immediately.

I'm sure 1/4" line would be fine, it's nearly the same as 3/8".