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

[marko138]

Johny...that looks great. I'm interested to see it mounted. Post pics when you do.

 

[Baal]

Johny Kidd: What are the dimensions of the tank? Did you do any baffling or fill in there to act as a condensation point or catch medium for the oil vapors? +1 on wanting to see pix. Planning on producing those??? [cool]

 

[dave_xb12r]

I don't know much, but I would be reluctant to face the filter into the wind. I don't think you want positive pressure on the downstream side of the breather system. Hopefully more tech-savvy folks will comment.

I placed my filter in the front with a hose running down near the kickstand bolt. I figured air passing over the filter and air flowing around the hose at the bottom would cause negative air pressure causing air to be pulled out of the crank case. I have had zero problems and I rarely have to clean my filter.

 

[Johny Kidd]

Johny...that looks great.

-Thanks ! [cool]

Johny Kidd: What are the dimensions of the tank?

-It's welded from square profile pipe which outer diameters are 20mm x 80mm (millimeter). There is no baffling inside the can, just empty pipe.

I did modify it a little since the pic was taken and now its waiting for new paint. I will post a pic when ready and installed!

Planning on producing those???

- Maybe, I'll let you know if i do

btw. sry my bad english

 

[mcdonald1983]

Has anyone done the breather mod and had problems with it or gone back to stock? I have a buddy that did it to his and hated it? He claimed you had to drain it all the time and and the bike seemed to spit and sputter more. Anyone hear of this or have this problem?

 

[marko138]

I have not had a problem. I do pop it open and drain it pretty regularly...but other than that I've noticed absolutely zero difference over stock.

 

[bajabomber87]

For the Commiefornia bikes

I just pulled the hose off the carb and glued a bolt in the hose and tucked it under this connector

Then for the fuel tank I zip tied it to the air box

 

[Johny Kidd]

Here ya go. Some pics of my breather setup.
It needs just a couple hose clamps and it's ready.

[s
sorry about crappy pics[sad]

 

[wiznut]

bajabomber87
Then for the fuel tank I zip tied it to the air box

Why did you plug the fuel vent tube???

According to the owners manual
http://www.buell.com/om/99474-09Y_en/file-8.asp
a "Obstructed fuel tank vent valve or pinched vent tube." can cause "Starts But Runs Irregularly or Misses"

 

[MickD]

^ yup, the tank needs to breathe. As the motor consumes fuel the empty space needs to be taken up by air. Otherwise you create a vacuum in the tank and overwork your fuel pump. I bet when you remove the gas cap you hear a sucking sound now.

 

[dave_xb12r]

Yeah baja, there is a loop behind the left rearset that is meant to hold that hose. It should be routed down there in case of an overflow.

 

[browland]

hey guys am I supposed to have a hose running over my rear shock and ending right above my rear fender? I was wondering if maybe the person who had my bike before did this mod or if that is factory

 

[dave_xb12r]

it should be routed through the loop behind the left rearset

 

[bajabomber87]

Haha funny I come back here and see this, already fixed!

I just put a bolt with a hose clamp on the end of the drain (not pictured)

 

[browland]

hmmm my hose im wondering about doesn't look like that it doesn't even reach to the top of the tire[confused]

 

[bajabomber87]

Can you take a pic of the hose so we can help out?

 

[browland]

yepers I will try and get one as soon as I wake up next year

 

[bajabomber87]

Have to add my conclusion,

Singlehandedly the best thing I've done to my bike besides putting the pipe on it. Such a big difference in torque from takeoff without having a worry in the world about it stalling. I actually dumped the clutch today with only a **** hair of throttle and it wheelied from a stop. No hesitation what so ever.

Now keeping the front end down is becoming a big worry

 

[mcdonald1983]

Bomber is yours a 9 or a 12?

 

[bajabomber87]

1203!