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

[Stangxb12r]

So when you say "re-calibrate" the ECM. Does that include pre-08 models??? I heard that when you do mods the Pre-08 models wont re-calibrate unless you have a program for the ecm??? Kinda lost, so any insight would be great. Looking to tackle a DIY project.

2007 Buell Firebolt XB12R
5800 miles
Buell race exhaust
Header wrapped, not sure if its aftermarket header??

 

[cannibol]

I have a stupid question. What purpose does this set up serve? I'm always up to enhancing my ride.

 

[Krayy]

I did this mod last Thursday on my XB12STT.

I went out for a ~200km ride on Sunday with 80km of it dirt, and the low speed surging issue has all but gone. Makes riding dirt a helluva lot easier when you don't know whether you'll get around a slow speed corner without the chance of a surge induced high side.

Props for the mod creators!!!


P.S. Car parks are easy as now. I was thinking of putting on an XB9 primary sprocket to make low speed easier, but now I'll keep the std one.

 

[TechMagic]

I have an 04 XB12S with full race kit, with this mod will I need a tune?

 

[dave_xb12r]

No tune required. Do the mod, you'll like the results. [up]

 

[TechMagic]

good, good. I'm mid-mod since I'm doing a bunch of other stuff, so I have a question.

Dave I think it was you who said just having the hoses join together and run back off the bike, will cause downdraft vacuum on the system and draw out oil, no breather filter required. That's my plan but is that your setup? and if so how's it working for you?

Also what is the consensus on Tasha's setup with the filter higher than the valve covers (though it should be located out of the airbox)?

 

[dave_xb12r]

Dave I think it was you who said just having the hoses join together and run back off the bike, will cause downdraft vacuum on the system and draw out oil, no breather filter required. That's my plan but is that your setup? and if so how's it working for you?

Sorry for the very later reply. I have a filter right up front, and the hose runs down a little past the side stand bolt(basically lubes the side stand spring lol). The way I figured it is the air enters the filter and travels out of the bottom hose creating lower air pressure above the filter drawing out dirty air and liquids. Being how the filter is in front, it gets dirty faster, but other than that, it's worked out well.

 

[Bill2]

I did this mod 6 months ago and the rear cylinder gromet leaks and gets into the cooling fan and shorts it out. Has this happened to anyone else? Any fix? Thanks.

 

[ADAMLEE]

No but I'll chech mine knowing there's a possibility.
Thanks for the heads up!

 

[Rocky Bar]

Just did my XB9 City, noticed slow speed was alot smother. Thanks for the great info. I'm new to this site and Buells. What a fun bike to ride. Next is exhaust / air box / K&N, etc. Cheers.

 

[Stevenc150]

I did this mod 6 months ago and the rear cylinder gromet leaks and gets into the cooling fan and shorts it out. Has this happened to anyone else?

Have you checked to make sure it's seated in the head real good. I seem to remember pulling mine partially out by accident and having a bit of a hard time getting it in.

 

[Bill2]

Stevenc150 thanks for the reply, i had the shop fix it and replace the rubber grommet and install a new fan but they said it would just happen again with the mod i did. I can't see anyway the mod would pull on the grommet anymore than how it was stock? Anybody with any ideals? This is my only transportation 20 miles from town. BTW after 200 miles its leaking oil all in the fan again, This sucks bigtime!

 

[Joe Deasy]

I did this mod on my new Ss and couldn't be happier about it. There's a 1/2 dozen threads on here about it and I think I read every one before I did it. so much thanks to all who contributed!

If it werent a brand new bike, I would have gone the cheap route and terminated the hose into a $5 paper filter, but since it was new, I spent the money and bought the best catch can kit I could find:
http://kdfab.com/Accessories.htm

Even if I didnt buy it, the printable instructions are useful:
http://kdfab.com/catch can instructions.htm

Only problem I had was with the hoses that came with the kit. They are pre-cut to the size for MOST models. They are a bit too short for the Ss, so I had to cut new hoses about 3/4" longer than the ones pre-cut for the other models (I used the extra hose they give you in case you want to route the filter to the tail). The kit comes with a metal breather filter that can be screwed into the back of the can, out of site.

The kit is over-priced, but if you've got the money, and you want the most professional looking installation, I would recommend this kit. For me it was worth $$ for the clean stock-look, and because there's no maintenance other than emptying the can once in a while.

My only complaint is that I gotta do this $%#&ing mod in the first place. As I see it, this aint a "mod". It's a fix.

 

[RT Performance]

here another idea it grabs attion and makes everyone look twice 2.50 catch bottle

crappy cell pics and i havent rotated them lol

 

[flaya564]

thanks you for the pictorial instructions

I'm getting ready to do this mod but Had one, single question.

Is it better or worse or doesn't matter to use Urban Assualt's version with two hoses or, Thaloc's where he connects the original hoses with a T connector and runs a hose back.

Thaloc's seems quicker and simpler but I feel there may be a reason to keep the hoses separate.

Please Advise.

Thank you

 

[RT Performance]

Stevenc150 thanks for the reply, i had the shop fix it and replace the rubber grommet and install a new fan but they said it would just happen again with the mod i did. I can't see anyway the mod would pull on the grommet anymore than how it was stock? Anybody with any ideals? This is my only transportation 20 miles from town. BTW after 200 miles its leaking oil all in the fan again, This sucks bigtime!

is one of your hoses short or binding the gromet?
i used both stock elbows and reversed the front and rear where i added the t.
I see no advantage to running the hoses seprate to a bottle.
better pic of my set up

My riding buddy nearly fell off his bike when we met up yesterday LOL

 

[Vabbott]

it looks like this mod has been done to xb12's would one follow the same exact steps for an xb9

 

[flaya564]

I have an xb9s and I used Thaloc's version (two hoses into one) and I'm impressed with how it smooths out the low speed cruising. Well worth the time and effort.

 

[Jornum1]

Another cheap alternative catch can is a small air line water separator. You can find them at lowes or home depot for less then $20.
I know its been posted before, lots of people have done it.
Just unscrew the glass piece take the filter part out and your good to go. The valve on the bottom isnt worth crap, so you need to either get a better one or plug it up. I just ran a 1/2 tap through it and used a set screw with some locktite red.
The inlet side comes from the crank case, and on the outlet put the small filter.
Its nice because you can see how much is in there. You then just unscrew the cup and dump it out.
Its amazing how much gunk comes out after a nice spirited ride.

Sorry I dont have a better pic, but you can see it right under my air scoop behind the oil cooler.

Better pic of the part.

 

[Buellysses]

I chose a little different routing, what do you guys think?

The hose snakes behind the rear cylinder, I zip tied it to the line that runs down to the oil pump to keep it away from the engine. Just crammed a bolt into the end to act as a plug. Sorry for the shatty pictures, it was late and I was FAR too lazy to get out my camera.