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

[Buellgog]

heres my attempt using chrome plated 8mm copper tube with a ball o fix valve bit fiddly to solder but works great

 

[BikerTrash]

I redid mine today like j4nn3, except I couldn't fit my filter there, I stuck it just under the voltage regulator. I still have to get another foot of hose and a radiator drain cock, I tried a catch can, but they were just too bulky. Pics eventually. [up]

 

[pamver]

cool looking catch can:
http://www.twinmotorcycles.nl/webshop/artikel.asp?guid=YXHFSC&aid=1903&cid=5365&s=&a=

 

[onelogue]

And back on issue what do you think I should do about the leak?

Hey Thaloc, you ever figure out where the leak was coming from? Sure its not coming from the rear rocker box? .... Many bikes including mine have problems with bad rocker box gaskets.

 

[BikerTrash]

 

[RedWhiteandBuell]

Did my re-route a few weeks ago. Just took a couple pics of the filter and catch can. The rest of the setup looks pretty much like everyone elses.

I did the mod with around 400 miles on it. There was no oil or crud in the air box at all. It has 700 miles on it now. I haven't checked the catch can yet. Before my next ride I'll see if there is anything in it.

 

[BKKBuell]

Hi breather experts
I read so many treats about the breather rerouting, so many things about performance and so on, oil and dirt, filters and separators... but I did not get a glue what the real reason for these breather is… and what the actual benefit of the rerouting is.

Can someone explain this for me stupid guy…

BTW: I found no oil or dirt around the breathers, I removed them once, closed the intakes on the CylHeads and the bike performed wonderful. So WTF is this piece of engineering on my bike

 

[bardo688]

Can someone answer my ?
Been though the whole thread...
So reroute...breather to the catch can then the filter. Do I close it off after the filter or run more hose past it?

 

[BPlass]

BKK and bardo, this linkbreather mod should help both of you out.

-Ben

 

[BPlass]

This is also a mod I have been looking at doing and have read several threads on it, my question is if I will have to do anything to the ecm with doing this mod? I have exhaust already, but still stock everything else. BTW my bike is an 05 xb9sx.

thanks

-Ben

 

[Stevenc150]

Breather reroute requires nothing to be done with the ECM or TPS.

 

[xxspudxx]

I have noticed my filter smoking at a red light a few times.

I have an improvised catch can. Photos below are my setup.

Ideas?

Looks nicer now after some heat shrink over the connections.

 

[Baal]

Pretty clean. What's the catchcan?

 

[Stevenc150]

With a closed catchcan, the crankcase gases that are expelled with each cycle have to have somewhere to go. Since you have a catchcan, the pressure is "backed up" and forced to travel out through your air filter. The blowby gases naturally have some oily vapor causing the "smoke". That's why I prefer routing with no catchcan so the pressure is released with little to no resistance.

As long as the end of the reroute hose is routed so it doesn't drip/leak someplace bad, the catchcans are just eye candy as far as I'm concerned. (I have mine routed down and zip tied under the left footpeg - have occasional residue that gets blown onto the swingarm, but nothing substantial)

 

[xxspudxx]

Thanks for the info Stevenc150. I thought about not running one, might wind up that way. So if I follow you correctly, Just ran a bit of hose down with no filter or drain?

Baal, the catch can is a oil/air separator for a compressed air system from Harbor Freight. Was cheap and seems to work really well.

 

[dorado29]

i'm thinking of running a bit of open hose instead of getting a can and a filter.. why haven't more people done that? it seems much simpler and equally effective?

 

[xxspudxx]

I think im going to redo mine that way.

 

[xxspudxx]

Ok, redone. Ran the line straight down the back and tied it off with the other drain tube.

 

[Stevenc150]

I added a filter in line before I understood what was really going on. With an open hose it isn't necessary but it looked kinda cool, can't hurt, so I've left it.

As far as why people have done it that way, that's how it's written up most of the time or they probably didn't want to chance drippage on their bikes. It's not wrong, more personal choice, but a bit overkill IMO. (I'm a K.I.S.S. fan.)

 

[upthemaiden]

I just did mine and it was a piece of cake. I only ended using 3 feet of hose, and that included replacing both stock hoses and cutting a chunk to fill the holes in the bottom of the airbox. I probably could've pulled it off in 2 feet had I reused some of the original hose. I just ran the hose straight down the front with the filter just below the air scoop and the drain going down right between the oil cooler fittings. I'm gonna go out and take it for a rest ride in a few minutes.