I have seen other threads in the past regarding modifying the AN Big Sucker breathing system to prevent oil/poop from getting back into the intake. Most just tap the AN backing plate and run some hose to a filter to let the oily air vent to the atmosphere, which is fine, but I didn't want any hoses on my setup.

I thought about it for awhile and decided to do mine this way:

1) Cut the ears off the AN backing plate entirely. Grind them smooth and hit them with some flat-black paint. Fill the old oil passage holes with liquid metal (JB weld).
2) Get the DK Customs thin intake bracket and black breather bolts that vent directly to the atmosphere after going thru 2 mini screens and filters built into the bolts. Install them on bike.
3) Mount the now modified AN backing plate over top the DK Customs bracket.
4) Get some longer allen studs to insert inside the mounting bolts that hold the air filter on for extra support strength. The stock AN studs are only 3/4" and I replaced them with 1.5" studs. Use loctite blue on both ends of the studs. (Probably would be fine with the stock studs but wanted to be sure to account for the extra width I was introducing with the DK bracket.)
5) Mount the air filter. Done!

Took the bike out for 100 miles today ripping down the interstate. No issues, no hoses, and only very slight microscopic oil mist out of the DK breather bolts, which I read is normal.

 

Thats pretty cool, the only thing stopping me from getting the AN big sucker is the fact that it vents back into the throttle body....

 

I could have just bought the whole DK Customs air filter setup but I didn't want a red KN filter. My AN Big Sucker uses a stainless filter with clear filter oil which looks much cleaner.

 

My plan was to get the DK customs kit as well, but I was thinking about it, and if I drill and tap the mounting bracket wouldn't some oil still be able to reach the channels that lead to the mouth of the throttle body? I mean, will the DK customs kit eliminate ALL of the oil from entering the throttle body?

 

You would fill the oil passage holes with JB Weld or similar in the same way I did. Then the oil can only go out your tapped holes.

If you get DK Custom's complete setup, then no oil can get in because all their setups are designed to use either the breather bolts I have or hoses routed to a small filter or the ground.

 

Thanks for the tip...decisions, decisions.....

 

The red (oil) in the K&N filter doesn`t stay red for long. Mine turned to clear or neutral after a couple hundred miles.

 

I was considering those breather bolts. Get back to us on how bad the oil mist gets on your engine, I might still do this to lose the hoses and filter if it's not to bad.

 

If you like the look of the Ness unit then you went the perfect way. I would have never really thought about combining parts from two different units like that, pretty ingenious!!

 

It's not much at all. Certainly nothing a quick wipe down with a rag after a ride can't fix. In fact, I find most of it goes on my jeans leg - and even then there's hardly any.

It's probably worse if you overfill your oil though.