The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Jmo on February 19, 2012, 01:47:02 PM

Title: what to do about oil breather hose?
Post by: Jmo on February 19, 2012, 01:47:02 PM

Hello,

after I replaced the standard air box in my 83 LS with KN filters I thought I could control the flow of oil out of the breather hose by stuffing some mesh in the hose.  Didn't work, too much oil comes out after a hard ride.  I've searched and searched for a filter to put in there but no luck so far.

I've seen japanese bikes sometimes use aluminum beer cans to collect the oil.  I'd rather have something else.  Does anyone have a suggestion?

Thanks

Title: Re: what to do about oil breather hose?
Post by: MR.E on February 19, 2012, 01:50:10 PM

why not extend the breather hoses to behind the gearbox?
that way if owt drips out, it can dribble at it's leisure.

Title: Re: what to do about oil breather hose?
Post by: Bob_Roller on February 19, 2012, 02:06:05 PM

Try putting that mesh material inside of the crankcase breather valve area .

It gives the oil that's in an atomized state something to collect on and drain back into the oil sump .

It won't stop the oil, but it will reduce the amount .

Also try keeping the oil level at around the mid point on the dipstick, some owners say that it helps reduce the oil in the breather .

Title: Re: what to do about oil breather hose?
Post by: steve hawkins on February 20, 2012, 04:44:32 AM

I have a small mesh filter on mine.  I dont keep topping my oil to the max and have little issue with excessive oil coming out.

I found my Filter in a local car shop (Halfords).  Its for the 'max power boys'  - a brather for the rocker box or something.

Let me see if I have a suitable picture.

You should just be able to see it on the cover plate where the old clamshell airbox was

Rev. Light

Title: Re: what to do about oil breather hose?
Post by: Jmo on February 20, 2012, 12:16:38 PM

Hey guys thanks for the answers.  Not finding that cool looking filter so far, Steve, but will keep looking.  I think I may try a combination of approaches, including mesh and perhaps a small plastic bottle zip tied to the cover somehow. Don't want to extend hose to face the ground because of the off chance of oil hitting the rear tire.  Below is what I found in an ATV site:

Drag bike owners usually take it a step further. They purchase flexible copper tubing and bend it into a vertical cork screw or pig tail shape before using it to replace the OEM breather hose. This ensures that the oil has a much greater distance to travel before reaching the airbox. Oil goes into the tubing and works its way round and round the cork screw, but never gets to the airbox, it just drains back into the engine at the end of a run.

Title: Re: what to do about oil breather hose?
Post by: steven m on February 21, 2012, 11:43:03 AM

Once upon a time I had a big old Honda 750F with K&N's and headers, so I rigged up the crankcase breathers ala grand prix bikes, which was clear plastic tubing to the back of the bike, past the rear wheel.  This allowed plenty of space for the engine to vent without constriction and for the oil to condense and run back into the crankcase when it cooled.  Just make certain the breather fitting is the lowest point so it doesn't puddle.

Steve

Title: Re: what to do about oil breather hose?
Post by: Jmo on March 30, 2012, 01:31:43 PM

Finally took a picture of my "solution."  An old plastic container from a spray bottle clamped to the rubber hose.  Drilled a few holes for breathing and done!.  Functional but not pretty.

After a hard ride I noticed oil collecting at the bottom.  Guess after a few months it will be time to empty the container.  No worries til then.

(hope the pix uploads; had trouble last time in this computer)