Another oil Leak?!?!?!

[Julio A.]

I fixed the leaking final drive last weekend, I found out that the rear brake shaft/cam has only one o-ring installed instead of 4. After fixing it, I enjoyed three days of no Leaks of any kind

But things never did go without problems for long....

Ok, before I went out this afternoon to update my registry with the R65, I noticed another oil droplet on the ground; Before, there was a leak at the oil sump but a new gasket fixed that, there are no signs of leak whatsoever on the oil sump now. I placed a cardboard sheet below the bike to pinpoint the location of the leak and found out that it comes right behind where the oil sump is, somewhere below the airbox.

I'm kinda stumped since i really don't know where oil could come from there.

[Bob_Roller]

Not too uncommon for the rear main seal to leak .

Look under the transmission back towards the engine in the shelf area, might me wet from leakage here .

There also is a rubber drain valve at the back of the air-box, an odd fish mouth looking part is any appreciable amount oil liquid accumulates in the air box, it will come out here

[steve hawkins]

I you keeping your oil level topped up to the top level on the dip stick?

Often these R65's find their own level and like to be there.  Any excess ia blown out of the breather.

It might be worth monitoring the oil level and try not to top it up unless it goes below the dip stick.

Over filling will just mean that she will just want blow it out where ever she can.

Just a thought.

Steve h

[Julio A.]

Well, I did just top-up the oil up to Max level before the droplets occurred.
I hope that's the case, I am not looking forward in replacing the Rear Main oil seal. I did notice that the R65 was consuming a lot of oil since the level went down quickly from max to a little above minimum. I thought It was consuming a lot of oil so regular top-ups were required.  It might just be that it does spit it out on the breather and levels by itself. I'm keeping my fingers crossed till I wake up tomorrow morning.

[montmil]

Could be the neutral switch weeping oil; and that stuff will migrate to weird locations. I had to replace this switch on both my R65s and the leaks went away. The Motobins pattern switch is superior -and cheaper- than the BMW OEM part.

Monte

[Julio A.]

It's not the neutral switch; It was just replaced last year, I also double checked it.

I checked it earler this morning and...
It's the Airbox! It's filled with oil! The problem I also saw was that the Engine Breather hose that has a funky bend that is connected to the airbox is starting to crack and chap.

I drained the oil; it needs an oil change anyway.
I'll be remembering not to fill it way up to maximum.

[Julio A.]

I know this might sound stupid, but when you measure your oil level do you have to screw in the dipstick?

I filled it at maximum when the dipstick was not screwed in.
I'm afraid I overfilled it too much, there are new oil leaks
this afternoon at one of the pushrod seals.  

[bruce_launceston]

I believe the oil level is checked with the filler cap not screwed in, just sitting on top of the threads.

[montmil]

Airhead "street tech" says to fill to the mid-point on the dipstick's min-max markings and check oil with the stick unscrewed and resting on the oil filler hole. Excess oil will be pumped out -most often into the airbox area- due to the airhead engine's venting design.

The funky rubber vent tube is a very pricey replacement item from BMW dealers. Two options for a cracked unit: Motobins sells a repop at a quite reasonable price or do as I did a couple years ago... clean the tube as best as you can, then smear some silicone adhesive into the cracks. As there is no interior pressure on the tube, the repair will hold for many years.

And a sidebar note: I recall one of our own hereabouts had a newly fitted BMW neutral switch fail less than a year after install. The part is rated "junk" on the Shopping Network's quality scale. 8-)

Monte

[nhmaf]

+1 - oil level is checked with the dipstick cap unscrewed and resting straight on the oil filler hole.   As long as the oil level measures to be in between the max and min marks, you are perfectly fine.  All the airheads I've owned like to be in the middle of the range between max and min - filling them up to the max level just means more oil getting blown into the airbox and carbs.

[Semper Gumby]

Hi Julio,

Which breather valve do you have?  The reed or the spring and the disc?

With the reed there is no adjustment but with the disc you can turn the disc over and get some life out of it.  You can also preload the spring by putting a small washer in first and then put the spring on top.  I would only put one washer on as more is not necessarily better.  This might reduce "some" of the oil heading into the airbox.  Don't drop any parts inside your motor.  That would be "bad".

I wonder if this is a sign that the cylinders are worn and you getting a lot of gases bypassing the rings.

Good luck.

[Barry]

Another method of adjusting the spring tension on the disc type valve is to use the lower groove on the central post (just visible between the the first two turns of the spring) intended to be used for the larger engines.  I've never tried it though.