Preface

Your /5 and later airhead motorcycle lower end has a well-deserved reputation for reliability and exceptional long life.  This remains so if it is kept properly lubricated.  Regular oil and filter changes based on both time and mileage are required.  There have been a large number of different filter numbers, filter styles, and methods of fitting them and associated parts such as O-rings, gaskets, shims, and oil cooler attachments over the years of airhead production.  This article will attempt to cover all versions,  models,  situations.  HOWEVER, the Author's website has several articles, number 49 through 52D, that SHOULD BE READ; these cover things in even more depth; things you NEED to know.  Please be sure to read all those articles.

Failure to follow procedures, particularly on /7 and later models, or any model with an oil cooler, can result in $$$ repairs. There is a critical white large rubber O-ring used on the outer cover on models with oil coolers, and later models without coolers. That O-ring must be in good condition, and under proper pressure, in the proper way. A failure here can result in an engine rebuild costing at least $2000; and if the crankshaft failed badly, perhaps over $3000. Reading this entire article will make you an INFORMED owner.   READ the other articles on the Author's website, articles 49 through 52 D.     http://bmwmotorcycletech.info

This article was completely revised by the author, on 01-04-2007; and updated on 12-10-2007.

The Basics: 

If just changing the engine oil, and NOT the filter, take a 10 mile minimum ride to warm the oil. Remove the engine pan drain plug, drain the oil, replace the oil drain plug using a new crush washer, torque to specifications, top up the oil to the proper mark (NOT screwing in the dipstick when taking a reading).  If you are also changing the oil filter, things are more complicated, particularly so if you have an oil cooler. I will get into these complications and technical details in this article. 

This is the abbreviated information:
Once the old oil filter is removed and the new filter and other parts installed, you then have an oil chamber (canister) area that is relatively empty. All the oil from your engine's oil pump must pass through that oil chamber before it gets to the vital parts of your engine. You want to fill that canister chamber with oil, pressurizing the system, while putting only a light load on the engine. 

The standard method is to use the starter motor to crank the engine, without allowing the engine to start. Some folks will remove the spark plugs, and make a tool for each spark plug cap, and thereby short the inside connection of the spark plug cap to the cylinder fins.  Others might just lay the spark plugs (with caps attached) onto the cylinders, with a sash rod spring wrapped around cylinder and spark plug, to keep the spark plugs positively in contact with the cylinder metal. Shorting the ignition by either method will protect the ignition parts, as would removing power to the ignition coil(s) primary windings. However, I do not advocate removing the spark plugs unless you need to for some other purpose.  What I do is to simply turn off the gas, empty the carburetor bowls,  and replace the bowls.  Then I crank the engine. The battery and starter motor are more than capable of the needed one or two each 10 second crankings. You can then ride to recharge the battery, or connect a trickle charger or Smart Charger.

On the center-stand, drain the warm oil from the oil pan (yes, warm...it is always best to take a ride first, that warms the oil, warm oil drains much better than cold oil).
If you have a magnetic drain plug, inspect it for particulate matter. Some fine powder, not feelable particles, is OK. If you do not have a magnetic drain plug, get one. The F650 magnetic plug 11-41-2-343-498 fits, and so do aftermarket ones from your BMW dealer.  Don't overtighten.
Some folks like to do a particularly thorough oil change, and drain the cooler. BMW no longer says the cooler has to be drained. I agree.   If you are changing the filter, the oil cooler, if you have one, will drain anyway.
If you are draining a cooler, or need to unfasten the hoses/pipes at the oil canister cover area in order to remove and replace the filter, then UNscrew the two 17 mm banjo bolts, letting the hoses hang down and let the cooler drain. It is BEST to use a socket wrench on delicate banjo bolts, to avoid distorting them. When reinstalling these banjo bolts you WILL BE using a torque wrench! AND, FOUR fresh aluminum solid washers!   Have them at hand and available!
Change the filter and associated parts, replace the banjo bolts using the 4 new washers. Note that these washers almost always will get a metal deformation, and reuse of old ones is a BAD idea.
Tighten the 17 mm banjo bolts to 13 foot-pounds. The absolute limit is 14.5 ftlbs. BE SURE your torque wrench is accurate. Be sure to retighten them overnight, or at least after a few hours. It is a good idea to position the outer hose away from touching a fairing, where fairing vibration could loosen the banjo.

With the fuel petcocks OFF, carefully remove the carburetor bowls one at a time, inspecting for dirt and water, and empty their gasoline. If your Bing CV carburetor bowl gasket is in poor condition, replace it, as a poor gasket will, at the least, affect the enrichener operation when in use if a tear is at the bowl corner area. Reinstall the bowls, leave the fuel petcocks OFF.
Put about 1-1/2 liters of fresh oil into the crankcase.   Turn on the ignition, the OIL lamp will light up.
Crank the engine until the OIL lamp goes OUT, this will take perhaps 10 seconds.
IF you drained the cooler, and your motorcycle has the BMW thermostat, you could now separately refill the cooler, failure to do so can possibly cause damage when the thermostat opens, with a large high pressure surge into the cooler. This step is NOT necessary with the NON-thermostat GS models with oil coolers. Some GS outer cover plates had a too- small hole for oil passage internally, this is described later herein.
To refill the cooler that has the thermostat type of oil cover plate, install the special factory bolt.  This has a long hex, and the length is  23 mm thread length (BE SURE it is 23 mm!!) and this special bolt has a  heavily rounded tip!!!  Install at the bottom of the thermostat, with the old washer, finger tight but up fully, in place of the much shorter bolt. Again crank the engine until the OIL lamp goes OUT, this will take a few seconds at most.
Turn on the petcocks, start the engine, let it run a minute or two, and look for leaks.
Shut off the engine, wait at least a minute and then recheck oil level. BMW airhead oil levels are checked on the center-stand, or balanced, and the dip stick is NOT screwed down when taking a level reading. Top up the oil as required.
Don't forget to retorque the oil cooler hoses banjo bolts at the thermostat, I recommend doing that overnight, to let the aluminum parts settle.  Remember the caution on the outer hose touching the fairing.
HANG THE FILTER TO DRIP-DRY, OVERNIGHT.    The next day, after you re-torque the banjo bolts to 13 foot pounds, take some large dikes or pliers, and carefully PRY OFF the metal ends.  Cut the perforated outer wrapper with a knife, and unroll the filter completely. Look for metal or other particles on both sides of the pleated paper. A few minor ones are relatively important, unless finger- feelable. Plastic bits come from the chain guide, and the color of any metallic bits will identify their origin.

The Important "Other" Stuff:

Oils of somewhat questionable properties tend to 'burn up' the first 1/3rd or even 1/2 liter, rather quickly.  This is usually a matter of the additive package, but can also be due to lower grades of crude oil base stock. Airheads with the smaller volume crankcases, especially pre-1980, tend to make the situation worse, sometimes from added crankcase pressure from thrashing parts as well as blowby (gases getting by the rings); and, especially, in combination with the old-style round disc breather. Except for the very earliest Airheads, the later ones have a TINY drain back hole for condensed oil, located in the breather area compartment at the bottom, it could be clogged, and cause excessive oil consumption, and even contribute to spark plug fouling.    Engine condition, in particular the rings, valve guides and style/condition of the breather valve, and that hole, have quite an effect on oil usage.

It OK to change the filter and any O-rings, etc., depending on your usage, at every other oil change. Likewise, it is OK to extend the oil drain period, mileage-wise, if you are on a long tour. Those doing stop and go city commuting, and especially those who do mostly short rides of under 20 miles, should change the oil MORE often. Generally speaking, under average use with non-premium oils, my recommended change is every few months and 3000 miles, whichever comes first. Premium oils usually can go twice as long, and sometimes longer than that.  For almost any normal use, changing the filter at every other oil change is all that is needed.  That does not apply to the first change after an engine rebuild.

Tightening the banjo bolts to over 14.5 foot-pounds is likely to result in shearing them off.
Deeper headed allen screws, compared to the original somewhat shallow headed allen screws, are available from your dealer for the three outer cover screws. They tend to round-out far less. Getting access to them, especially on faired bikes, is not REALLY a problem....use a cut-down short leg allen wrench, some like to also have ball-ended T allen wrenches, and you can put a small hole in the fairing, etc. Do use locking or waverly type washers. Do not overtighten these screws, they can be difficult to remove. It is acceptable to use a faint smear of anti-seize compound on the threads and washer.   Always draw the screws up evenly and squarely, going back and forth on the three of them.
Do not use single weight oils, unless you have a problem breaking in the rings on a newly ringed engine. Do NOT try to break in an engine on full synthetic oils.
The OIL light must NEVER come on ANY time the engine is at idle or above...UNLESS you have a faulty oil sender switch. There is a rare exception under very hard front braking, for a second or so with very hot oil, and in some cases only slightly low. If the oil light comes on at idle or above...stop the engine right now...no waiting! The problem is likely the switch...or a sliced 11-42-1-337-098 large white rubber high pressure area O-ring. It really takes very little time for low oil pressure to damage your engine.    NOTE that if you have never had the oil pan off, you should do that once, and make sure that the oil pickup is assembled properly, the bolts and gaskets in place and tight, and the two bolts, if you find them loose, should be removed, cleaned, lightly coated with Loctite BLUE, and then reassembled with fresh paper gaskets.   When replacing the pan and gasket, things must be VERY clean, non-oily, and use a cross pattern in tightening the pan bolts, and do NOT exceed approximately 72 INCH-pounds on them. Absolutely NO oil on the mating surfaces, and absolutely NO goops nor sealants on the pan gasket!  NO nicks.  Do NOT use a screwdriver blade to pry the pan off the engine!

NOTE: very old part number prior for the white 11-42-1-337-098 O-ring was 11-42-1-264-160.

NOTE: The stock oil pressure switch activates at an oil pressure of approximately 3 to 8 psi. Generally speaking, even with hot and thin oil, the oil pressure will not fall under 15 psi. BUT, in a few rare instances, especially with thinner oils in very hot weather and/or with extreme stop and go traffic conditions, and even more specifically with an old worn engine....the oil may heat up enough to thin it enough and to cause the oil pressure to drop enough to activate the OIL lamp. It would be a good idea to turn the engine off and let it cool down.     If the oil pickup gets loose (I have seen them actually unfasten and fall into the pan!) the light may activate with slightly low oil level.   I am a strong believer in removing the oil pan for inspection once.

NOTE: Excessive low rpm idling is BAD for the chain, the chain guide, and the sprockets, all of which are oiled by overflow from the oil pressure relief valve, which may be nil at such idling with very hot oil.

The oil pressure lamp will illuminate for your pleasure for several other actual and real purposes:
#1: You are shortly to be pitched over the handlebars from a seized engine, and you have already damaged your engine.
#2: Your bank account is going to be drastically affected very soon.
#3: You want to know that the filter chamber or oil cooler is refilled.
#4: You are VERY low on oil, and you may have already damaged your engine.
#5. You like to know that the oil lamp is working before you start the engine.
#6: You like to get the very last day of the very last month of the very last year of usage from your battery.
       You enjoy hearing, on that last day, the starter click, die, and then the oil lamp go out too.....as the electrical system  has died and gone to battery heaven.

The thermostat seldom fails. They have been known, RARELY, to stick. This does not have any real effect on engine oil flow. The thermostat is NOT simply an on-off valve. The wax valve inside it slides and determines, from temperature what percentage of oil is routed to the cooler. Use of the wrong special drain bolt at the bottom of the thermostat can seriously damage the WAX thermostat.

MORE of everything you wanted to know (or not), and then some:
 
OAK (Orlando Okleshen) wrote articles over the years covering much of this subject matter, published in the magazine of the BMW Motorcycle Owners of America. This was called BMWNEWS, now BMWON (BMW Owners News). These OLD issues will likely be difficult to find, and are no longer needed, as he treated the subject in some depth in AIRMAIL, the publication of the Airheads Beemer Club, in the June 1997 issue, with follow-ups in the July 1997 and the August 1997 issues. Most comments made on this subject, after the June 1997 article, will refer to this SUBJECT as the "$2000 O-ring", which was coined by Oak.     If you have a severe oiling failure, you will...or can... ruin your crankshaft, and the bill will be upwards of $3000+ for a total engine job. Crankshafts are usually NOT 'turnable' for oversize bearings. I recommend, not idly, that you obtain and read those articles in AIRMAIL if you can, as they may help clarify some of what I have written here.  That is because Oak and I have different writing styles and methods of explaining things.   If you can not obtain the past AIRMAIL issues, at the very least go to this author's website and read the much more comprehensive articles on the oiling system.   In particular, see articles numbered from 49 through 52D.    That website also has an oiling system sketch, and allied articles.   The website is:  http://bmwmotorcycletech.info

Information published in the popular Haynes and Clymer's manuals MAY be wrong! Certainly some of it is confusing, not the least of which are errors in sketches in one version of the Haynes manual on the parts fitment in the oil canister area. BMW has published some information, particularly sketches covering, unbeknownst to you with a quick glance, that cover many years.   Those BMW sketches, and some other literature are also misleading, to say the least. It is sometimes what is NOT published that causes problems.

The earliest airheads such as the /5 and /6 series (UNLESS CONVERTED TO USE A FACTORY OIL COOLER), up to a change in 1976, had a 3 bolt outer cover, but inside was a single large bolt (17 mm) metal cap cover, that fit over the oil filter canister. NO inner cover sealing method was used to seal that inner cover to the metal canister itself. The fit was perfectly adequate in itself. On that type, with the INNER COVER, the OUTER 3 bolt cover MUST have a paper gasket. The original filters were semi-sealed to the inner side of the metal cap cover and to the far inner end of the canister, via two small rubber O-rings, that lightly push fit over the central oil tube. These now obsolete O-rings were normally replaced at each filter change, and removing the innermost one was done with a bent end of a straightened coat hangar.  If you are working on an early model Airhead, do check that those old small O-rings are NOT PRESENT; as they are obsolete, and NOT used now.    BECAUSE….later, these two small O- rings were eliminated, in favor of bonded-to-the-filter rubber ends. At one time filters were also available that had the bonded rubber only for the far INNER end, and one small O-ring was still used at the OUTER end of the filter. Do NOT confuse these words with the much larger separate O-rings now used on much later models withOUT the inner cap cover, which do NOT grip the central tube.

Note also that modern BMW filters have bonded rubber at both ends for the early bikes.

Later models eliminated the inner metal cap cover, including of course the large central bolt.  Those early metal cap cover models were basically just about foolproof, but they did not accommodate an oil cooler installation.  Many were modified for a cooler.  If you have an early model that has been converted to use the factory style oil cooler and thermostat, these comments are only for reference purposes, as you have essentially nearly the latest production version; that is, the central tube was changed, and there is no inner metal cap cover or bolt, and you have a cover  with two sizes of O-rings, and you use different filter models. When the oil cooler is installed on a motorcycle that did not originally come with a cooler, the central pipe is changed to a longer one, and the inner cap cover and bolt are not used.

After the inner metal cap cover was eliminated from all models, all airheads used just a new style of outer 3 bolt cover. Use here of the word 'cover' includes both cooler and non-cooler models. These covers, of which there were THREE different BASIC styles (no cooler, cooler with thermostat cover, GS cooler no thermostat) all had two Rubber O-rings inside. The larger O-ring  is the critical one.  Not only must that O-ring seal the canister from the crankcase (there is a small gap between canister and inner engine wall); but, the same O-ring must seal the outer cover. In early production, the smaller cover O-ring was actually a round one, 11-42-1-337-097, it is no longer available, and a square sectioned one is, or should be, part of the oil filter box parts.

NOTE:  SOME factory filter 'kits' do NOT have all the necessary parts, or have extra parts you won't use!!   There have even been filter boxes shipped without the proper O-ring. 

****The factory MIGHT have shipped the bike with a paper gasket at the cover.  That paper gasket MUST be used on the EARLY bikes that HAVE the INTERNAL single bolt cap cover.  The paper gasket, otherwise, should NOT be used, except in rare circumstances; even if the factory installed it originally;....AND,...the factory might have installed a shim at the canister that is almost always to be used. Much more on those later in this article.

OAK's $2000 O-ring article in AIRMAIL was prompted originally by an inquiry from someone who did major damage from using a too thick outer gasket (a soft silicon 'lasts forever' aftermarket item), when no gasket at all would have been just fine, and obviously preferable.

What is often not understood properly is that the metal shim, that is installed IMMEDIATELY after the filter, is there to protect the large white O-ring from being damaged by the sharp edge of the earlier canisters, and ALSO to increase pressure on the large O-ring.

****The right side open end of the canister is NOT part of the outer engine wall!    There is a small space I will call a gap, between the outer end of the canister and the inside wall of the engine. The MULTIPLE purpose of the large white O-ring is to seal that space and also to seal the canister to the outer cover. If this O-ring does not seal perfectly, the high oil pressure inside the canister, which comes DIRECTLY FROM THE OIL PUMP can leak into the oil pan/sump. This will reduce oil flow in the engine, and it can be a drastic reduction. If an outer gasket on the 3 bolt cover is used, and that gasket is thick enough, there may well be insufficient pressure on the large O-ring and its sealing may fail.   Using a paper gasket when not necessary, can cause you to not see any large O-ring leaking! Obviously the large white O-ring must be in perfect condition. It is foolish to not replace it any time the outer cover is removed!

****METAL SHIM: In late 1978 the factory began adding the metal shim. It was available separately, and the part number is: 11-42-1-336-895. It is approximately .011" in thickness, and of diameter to match the outer face of the oil canister. The earliest of these shims was made in such a way that one side had a sharp edge. If you have one of those, the sharp side goes INwards, and contacts the canister. The shim is ALWAYS installed as the FIRST THING immediately after installing the filter itself. The purpose of this shim, now packaged with most filter 'kits', is, as noted above, to keep the canister end from cutting the critical large white O-ring, part number 11-42-1-337-098; and, to increase the pressure on that O-ring.

****BMW manufactured late model canisters with a protective outer lip, probably beginning with the 1988 R100RS (MAYBE), this is not really very clear in books and literature.  This so-called 'lipped canister' supposedly does not need the metal shim. BUT...one must be very careful about not using the shim. In some cases, I have even had to install two shims, so as to have the correct needed pressure on the large O-ring. The important thing is that the 4 mm thick  -098 O-ring is squeezed well, yet not so much that one cannot get the outer cover fully seated onto the engine with normal screws torque. One can expect possible, not always though, SLIGHT deformation of the metal shim after use, and it is then replaced at filter changes. The White large O-ring WILL deform after enough engine heat/cool cycles, and MUST be replaced!! each and every time the cover is removed!!!   Very specific riteria for gasket and shim are below.

Airheads with coolers have the outer 3 bolt plain cover replaced by either a thermostatic controlled cover; or, in the case of some GS models, with a restricted orifices outer cover. NOTE: On the GS models with the non-thermostated cover, there is a factory bulletin on the cover. The bulletin says to inspect the small hole in that cover, and if 2.0 mm, to drill it to 5/32.   This will allow adequate oil to flow, even if in very cold weather.  In very cold weather GS owners are supposed to use a cover over the cooler.

The center pipe in the oil canister area has been known to loosen. Be sure it is very tight. If it is loose, perhaps by 1/8th turn or more, remove it, clean male and female threads with a good solvent, and use Loctite Blue sparingly, before replacing, tightly.

********
******** With regards to the later models (NO inner cap-cover), BMW has on occasion goofed in the installation of the canister. Sometimes it is set too far in, and in MORE RARE instances, it is set too far out. The depth of the end of the canister is fairly critical, as the O-ring must seal both the canister to the outer cover, and the canister to the engine casting wall, preventing oil from escaping the cover and escaping the canister area directly down to the oil pan. The actual specification for the distance from the end of the oil filter canister to the OUTER face of the engine casting is 3.0 mm (0.118").
NOTE that if this distance is over 3.0 mm (0.118") you must NOT use the paper gasket!! You MIGHT have to double up on shims too! The large O-ring MUST be under a goodly pressure...but not too much.
NOTE that if this distance is over 3.2 mm (0.126"), use of a metal shim(s) is mandatory, even if you have the very last production version of the canister with a lip.

****Under NO circumstances is a thicker than factory stock paper gasket, or doubling up of a paper gasket allowable, UNLESS you have a real, known, measurable reason. Use of a cover gasket, where one is not needed, can also mask some types of large O-ring leaks; where you might see them on the outside of the engine.

In a few fairly rare instances, supposedly on some R45/R65 models, but has been reported on some other models, it has been found that the canister depth is UNDER 3.0 mm. One MUST use the outer paper gasket to avoid excessively crushing and damaging the shim and O-ring.

The order of installation of parts is ALWAYS: Filter, shim, cover with the two O-rings, RARELY USED gasket on cover.

Canister Mania:

The canister part numbers are confusing.....and for you anal types, here is some information (??) I am not 100% sure of. The old books show that the canister for the oil cooler model was 11-11-1-263-343, which obviously must be a non-lipped type due to its age. In the early 1980's, the microfiche shows that the canister for the oil cooler models is 11-1-1-337-292. It might be the lipped canister, but the parts price book sends you back to the -343 number. In the late 1980's, the microfiche for ONLY the RS model!!....shows an erroneous (?) number for that canister. No microfiche before or after shows that part number, except as the central tube!   In 1990, the microfiche shows ALL cooler models using 11-11-1-338-203. If you go back and now look up the part for the earlier models, it shows this version. THEREFORE, AFAIK, the -203 is the latest, lipped, canister. Now that you know all this, it makes absolutely no difference, as you won't be changing your canister!

Filter Mania:

Quite a few manufacturer's make, or have made, filters that will fit our airheads. At one time I obtained filters from Purolator, Fram, BMW dealer, and one other manufacturer. ALL were boxed with information stating that they were for a BMW R-xxx bike. I did not like what I saw on a few, and I went so far as to send OAK some new samples for his eyeball. Both of us felt that pending laboratory tests we would stay with the dealer supplied official part.

Purolator: had 41 paper pleats, paper is of fine grade, proven quality, and the void space between the pleats was maximized. The pleats went deeper, the I.D. size well selected. From end to end on the I.D., the holes in the grating surrounding the center tube existed. The pleats were somewhat spread out, unevenly. The flow rate is proven acceptable.  An OK filter. (I used to purchase PL-17 by the case, same as the BMW part in every way….this was a LONG time ago).

Fram: 35 paper pleats. Paper is coarse, lessened void space, not as deep, so square area is less, I.D. is larger than the OK Purolator.   From end to end on the I.D., the holes in the grating surrounding the center tube go only about 2/3 of the way, and the remaining area is closed off, solidly. This reduces the flow rate. The pleats are spread out more evenly than the Purolator, a minor plus factor. The paper quality is questionable, seems fuzzy, and it MIGHT be decayed by the oil. Flow rate unknown. Oak recommended against this filter.

NOTE: filters were once available in bulk; and, now, are available as filters OR in kits from BMW with O-rings, shim and gasket, etc. Note that I consider replacement of the large white O-ring a MUST if the cover is removed. Be 100.00% sure that any -098 large white O-ring you install is absolutely perfect, without the slightest nick or cut, etc. Once the metal shim deforms much, it must also be replaced.   BE SURE that if you purchase a BMW filter kit, that the kit has every single one of the parts you need for your bike.

There are quite a few BMW factory part numbers for the filters. Some of the earliest filter part numbers are still seen now and then on someone's shelf. After someone visits a not so knowledgeable dealership it is not rare to find out that he/she has purchased the wrong filter or is missing parts for their motorcycle! So much for 'knowledge'.

In an effort to confuse the issue as much as possible, I offer the following, and NOTE that the Author's website has MUCH more information, especially on the KITS now available from BMW:

11-42-1-253-817: This filter is for NON-cooler airheads, it is rigid, and short. Used on /5 and later models. It is replaced by 11-42-1-253-919, which in turn is replaced by 11-42-1-337-198. You will be pleased to find out that the BMW Parts CD says it is replaced by the -572 filter.   See the -198 below too.

11-42-1-335-385: This filter is listed for 1979 to later RS/RT models with a cooler. It is rigid, and long. It is obsolete. Confusingly, some listings may not tell you that it is really for /7 and later, but NOT the R65, and NOT the R80GS, R80ST, R80RT, R100GS, and R100PD. There is no information, AFAIK, as to why all this nonsense is listed so confusingly and wrongly and differently here and there. My Parts CD says it is replaced by the -575 filter, a HINGED filter. AND, yes, the -575 is the COOLER filter; yep, the REAL number…see it below.

11-42-1-337-198: This filter is for non-cooler airheads, it is rigid, long, has 2 square O-rings, and is OK to use to replace the 11-42-1-253-817, but this -198 is replaced, in turn, with 11-42-337-572. Are you confused yet, by the -817 short filter being replaced by a long filter? Add to the confusion and see the -572 model. Add even more confusion: find out that the CD says the -919 filter and a -061 filter were in here somehow along the way. I personally have NEVER seen those last two numbers.

11-42-1-337-575: This filter is for use with the cooler equipped airheads, it is HINGED (two piece joined), and comes with 2 square O-rings. It supposedly has the same usage as the -385; and also it will replace the -385. Use it for the cooler equipped models. A hinged filter is the only one that I like, it is stronger, and MUCH easier to install.

11-42-1-337-570: This filter is for non-cooler airheads, it is hinged, comes with 2 square O-rings, and is OK to use to replace the 198. It is really the hinged version of the -572, supposedly OK for same usage as -385, plus the R65. OK for most 1976 to 1992 models.  I LIKE hinged filters!

11-42-1-337-572: This filter is for non-cooler airheads, it is the original single piece long filter, but it has bonded rubber at both ends. It might be marked, on the filter itself: BMW, OX35, made in Austria, 11 42 1 337 198. It is supposedly for 1969 to 1991 models.
 

So...what do you REALLY do about the filters? Your dealer PROBABLY has the correct filter number, which they can determine from year, model, and if you have a cooler or not. Unfortunately, some dealer parts folks are NOT very knowledgeable about airheads.  The filter part number, if you are lucky, will remain the same number for a long time. You may have a choice of a hinged filter or straight filter...and the hinged filter can make life easier, IF your airhead needs it, some surely do, and the hinged filter IS stronger.    BMW basically sells 4 filters, hinged and not hinged, for cooler equipped airheads… and not cooler equipped.   It is entirely possible that this could be reduced in the future to THREE models….or even two.

Some folks have been known to drill an almost unnoticeable small hole in a RT fairing, to allow easier access to one of the outer cover Allen bolts. The hinged filter may allow you to place the filter into the canister without removing things...like the engine, exhaust pipe, or crash bar. The angle and position of the hinge is critical to slipping the filter into the canister, without crushing or otherwise deforming the filter. You may need to experiment, then write down the exact angle, hinge position, etc.   For those interested in wee details, the FRAMES of some models interferes with the outer cover, so a non-thermostated cover was developed (GS models).  Some exhaust pipes were dimpled on the engine side.

Try to understand the description of the various methods of use of filter, shims, gasket, O-rings. All those filter numbers are not available. In fact, only a few are available. Kits are available, and MIGHT NOT have all you need in them, and might have extra parts too!   The author's website has LOTS more details.

Be sure you give the dealer the correct information on your airhead.  QUESTION that dealer if you have even a slight suspicion you are getting the wrong filter, such as the wrong length.

You should not be overly confused, after all, you understand just what goes inside that canister and cover...right???

PLEASE refer to the Author's website, and PLEASE read ALL the articles from #49 through 52D!!

http://bmwmotorcycletech.info

Snowbum
ABC 1843
Rev. 12-10-2007