Oil Leak at head

[fermin]

I am getting a continuous oil leak from the left cylinder while trying to  start the bike first time after an ebay purchase.  Gas tank emptied, cleaned petcock filter and used fresh fuel, jumping the battery with my car.  Couldnt get the engine to turn over more than 2 seconds.

The cylinder head cover was loose as I was planning to adjust valves later and noticed the oil leak.  I am thinking bad piston rings.  Anything else that I should check?.  

I am starting to spend more time in the garage than in the living room.....

[Bob_Roller]

Can you determine if the leak is from the valve cover to cylinder head gasket, or between the the cylinder head and cylinder gasket ?

If the valve cover was loose, it most likely is from that .

Not too uncommon, to have the center nut holding the valve cover on, to have stripped threads on the stud in the head .

I would start by checking the torque of the cylinder/cylinder head nuts, then check/adjust the valve clearance .

Not a lot of info to go on, what year bike, how long has it been sitting, how many miles/kilometers ? on the bike

[nhmaf]

IF you are new to airheads - note that the valve cover is really held on by the (2) 10mm nuts on the front and rear "corners" - they do most of the holding and should be able to seal the cover & gasket oil-tight even without the center acorn nut on the valve cover.

I'd recommend taking the valve cover off, and ONLY if you have a decent torque wrench or can borrow one, slightly loosen, and then re-torque the (6) cylinder head nuts in a criss-cross fashion to the proper torque (23 ft-lbs seems to come to mind).   THEN do a valve lash/clearance adjustment  - set intake/exhaust to ~ .004" and .008" respectively.  Then reinstall the valve cover and carefully snug it down but not too tight, just enough to get the cover to seal against the gasket and not leak oil.  You *may* have a torn or damaged/deformed valve cover gasket which is preventing a good seal, or it is possible that the PO put the gasket on wrong (they only go 1 way, but some people manage to put them on upside down.   In VERY rare cases, the head surface is warped and the standard gaskets won't fill the gap well enough to seal - there are thicker/softer silicone gaskets one can get to  address this if you don't want to send the head off to be resurface, IF that is the case (again, VERY rare).

[fermin]

Thanks Bob and NH,

Its a 1983 with 13000 miles that had been sitting in a garage for some time , at least since 2004 as the title was not updated by the person who sold it.
It ran at purchase (rough) after a jump start.

The leak is at the cylinder head.  Its contained until the cover is removed.  At the time I started the engine the cyclinder head central bolt was off and the two nuts loose, but how does that prevent oil from leaving the engine?.  Shouldnt you be able to run without the head (other than the nuisance made by the valves going in & out ) without leaving a trail of oil down the road?.  In the end even with the head correctly tightened down, the oil would accumulate there until filling the headspace right?.  Iam a tad paranoid so though of broken rings etc and even had a nightmare yesterday about the bike.

Today I re-torqued the 6 head nuts and adjusted the valves on both sides ( the clymer manual states 0,2 mm exhaust and 0.1 mm intake, and is a bit different from the owners manual wich has two settings during break-in and after x no of miles).

The left cylinder does not have the central cover bolt nor the nut.  The nuts on order but did not know about the bolt until I removed the right  cover.  Both gaskets appear to be OK.

So according to your diagnosis, bolt both covers to spec and crank it again. Correct?

Again thanks for the help provided.

[Bob_Roller]

The top end gets lubricated with engine oil, that comes up around cylinder hold down studs goes to the rocker arm bearings .

So yes you get a whole lot of oil in the valve covers, if you run the engine without the covers installed .

Once the oil is used, it goes back to the oil sump via the push rod tubes .

[nhmaf]

+1 What Bob said - This isn't a Chevy L-6 engine!
There are small "notches" or holes at the base of the cylinders - if you ever end up taking them off - around where 2 of the studs pass through.  This allows relatively low pressure oil to travel up those studs to the rocker mounts, so that they are lubricated.  IF the bike has been run and you take the valve cover(s) off without finding any oil in there- THEN you have something to worry about.   Lesson: don't run the engine with the valve covers off - your baby needs her blood!

[fermin]

Ahhh now it makes sense, I was thinking like the chevy engine, with thoughts of the movie Das Boat with the diesel engines running and all the valves tapping away.  I'm closing the covers and moving on.

Rotor-replaced
New front pads-replaced
check rear brake-done
moly spline-done
new front line brake line-on order
valve clearance-done
remove rusted gas tank cap-done.

Doing all this work reminded me of a book read long ago "zen and the art of motorcycle maintenance"

I hope to be able to ride soon, weather here's been great

Thanks again

[Rob Valdez 79 R65]

What year is your bike?

Do you have the Owners Manual?  

If not, see my sticky thread at the top of the page.

That small, $25 book has everything you need to get yourself started on the tuning process.  
You can even order it from a BMW auto parts counter, if need be.

[fermin]

Thanks Rob, its an 83 and I ordered both the owners manual manual and a Clymer manual, avidly reading through both.

[Rob Valdez 79 R65]

the owners manual has the procedure for resetting the torque on the heads.

If you don't have one, get a good torque wrench in this tightness range.

Ask questions if torque wrenches are new to you.

[montmil]

Ahhh now it makes sense, I was thinking like the chevy engine, with thoughts of the movie Das Boat with the diesel engines running and all the valves tapping away.  I'm closing the covers and moving on.

Do you also remember the greasy engine room crew crawling about with their oil pump cans; squirting lube onto the clackity-clacking valve gear? Some early aircraft engines required filling up oil cups that dripped lube onto the rockers. Some needed a squirt prior to every takeoff. Early radial A/C engines operated with a total-loss oiling system. Recalling the raccoon-eyed pilots sans goggles, the oil was castor-based. Due to inhaling and swallowing the oil plume, pilots, too, also operated on their own personal "total loss" system.  

Although the Beemers are often referred to as "agricultural machines", at least we don't have to carry an oiling can in the tank bag. But I digress...

As to your valve cover bits... you may find that the PO has stripped the threads in the cylinder head where the central stud fits. A new stud will just twirl happily in place. A helicoil threadsert will get you going. Inserts and the install bits are available at most auto supply stores.

Just snug down the center nut. Don't lay onto it too heavily. Just snug. Use a short handle wrench. Snug only. Did I mention "snug"? [smiley=thumbsup.gif]

Monte  

[fermin]

Thanks Montmil, snug's the word.  The left cylinder head had no central stud, nor cap.  Both are in order.  In all the conmotion one of the washers for the other two nuts is MIA.  Are these thin washers  available at regular auto parts stores?.  They are everywhere and the manual keeps telling you to replace washers.   My BMW dealer is a bit far.  I am going to be trying hard not to use Chinese parts on the repairs but for the washers 'dont ask dont tell' may be the procedure to follow

[Bob_Roller]

Those washers, commonly referred to as 'wave washers', due to the fact they are sorta bent in the middle, and act as a lock washer .

If you have Lowe's or Home Depot home improvement store in your vicinity, they have them in the common hardware in the metric section, usually in metal cabinets with pull out drawers, usually packaged in quantities of 10 or so .

[MrRiden]

ACE hardware also has metric wave washers

[montmil]

ACE hardware also has metric wave washers

Although the same ones at Lowe's are a lot less expensive! At ant rate, smoke 'em if ya got 'em.

Monte