R1100RS revisit...

["Tom Brown" <tbrown@xxxxxxxxxxx>]

Rob:

Don't know where I was when your original posts came out.   I don't know if 
I remember them.   Also difficult to tell what level of mechanical 
experience you're at. Sounds like your gaining knowledge the expensive way 
quickly, however.   Also sounds like you're listening to some pretty dubious 
advice from mechanics who may be covering their butts.    Some of the 
information below may be new to you.  Some may just fill in some blanks. 
Some may just be useful to other readers.

The rest is pure drivel.   For what it's worth...


Engine Damage:

Double Yikes is right!   You've single-handedly had more trouble with your 
RS than our entire club has had with all its oilheads combined.   I had a 
trans seal replaced on my '99 R1100RT at 32,000 miles under warranty.  This 
was a known assembly problem involving some metal flash in the orifice for 
the seal.  It didn't seat all the way on one side, causing it to be not 
square with the shaft.  A new seal and elimination of the flash solved the 
problem.  In the bargain, I got a spline lube for free because it's part of 
the procedure for replacing the seal.   That's all the major repair that 
bike needed.  I put 62,000 on it and my big concerns were things like the 
right tank bag, the seat, bar-baks, windshields and tinkering with the FI 
system to eliminate low and mid RPM surge, which I was able to do 
successfully.

I've now got about 20,000 on my '04 twin-plug 1150RT and, so far, no 
problems.  1,000 really quick miles this weekend and the bike is thriving. 
I ride it hard, but take very good care of the mechanical systems.

I do my own valve adjustments and throttle synchs, thankyouverymuch.   I 
trust my work over some random guy in a service department who needs to get 
the job done according to the time in some book.   I do take it to the 
dealer for service to the new servo brake system, which I've grown to love, 
by the way.

I will say that the sticker on the gas tank of the 1150 says you can put 89 
octane (mid grade) gas in the bike, but my experience has been that it runs 
rough under most conditions and pings under certain conditions with 
mid-grade.  I put premium in and immediately noticed an improvement, so I'm 
staying with it.   The late and great Rob Lentini also advised that 
mid-grade worked better in Oilheads under certain conditions.  His RS had a 
catastrophic piston failure too.   If you were using mid grade or regular in 
your bike or were using autolite plugs, which are slightly longer than the 
stock Bosch plugs, you have two possible causes for problems.

If you or your mechanic had too little clearance in the exhaust valves, 
(perhaps the lock nuts weren't tightened?) it would explain why they were 
burnt and could also explain the busted piston.   I'm gonna guess that the 
"pie slice" of your piston crown was from the exhaust side and that it 
either blew into your cat or is down in the oil sump somewhere.   Probably 
should find that before reassembling the engine, just to be safe.

Valve clearance theory is simple, but not obvious to the casual observer. 
Valve clearance or "lash" is needed between the cam and rocker arm (in our 
case, a small pushrod is involved) because, the long stem of the valve gets 
longer as the engine heats up, especially on the exhaust valves, which, in 
an oilhead, have twice the clearance specified as the intake valves.

If there is insuficient "lash" in the valve system, the heated, now longer 
valve stem close up all the available lash and the valve will be held 
slightly open open when it should be closed during the combustion cycle. 
This is bad, uh-kay?

The fire from the combustion process escapes out of the valve.    Very high 
temperatures result and you get burnt valves.  ("Burnt" valves are actually 
valves that have become too hot and have re-tempered themselves.  This makes 
them brittle and then they break off in little pieces that shoot out the 
exhaust).  Burnt valves are bad, uh-kay?   Once the compression starts to 
excape where it shouldn't, the whole area runs much hotter than it should. 
One item after another becomes superheated and changes temper and destroys 
itself.   This is true for any engine with decent performance.   Sometimes 
an old tractor engine with very low compression that can run on salad 
dressing will not burn a valve, but it is never good for the components.

Blaming the failure on "bad mettalurgy" is probably the dealer's way of 
side-stepping responsibility for the problem.   My guess is that the valves 
were either adjusted with too little clearance or the lock nut was not 
tightened and the adjustment closed itself up as the engine ran.   I've 
never heard of bad mettalurgy in a BMW product.   This is one thing they do 
seem to get right.

Now, also understand that the usual engine wear happens in the valve seat, 
the rim of the hole that the valve closed up.  The valves move quite fast 
and slap closed with some force.  This valve seat surface wears down as time 
goes on.   It's not the only wear surface, but it's generally the one that 
gives the most wear on most valve adjustments.  When the valve seat wears, 
it makes the valve lash smaller.  It's geometry.

Anyway, that's why valve adjustments are important.   Engines generally want 
to close up the lash as they run, so it's up to us humans to adjust the lash 
from time to time to prevent this lash from getting too small and preventing 
the aformentioned combustion leak and resultant engine damage.

The higher the compression and the leaner burning and more efficient an 
engine is, the more important it becomes that the valves not be held open 
like this.

Likewise, the quality of fuel becomes more important.   Hot weather and 
sub-standard fuel are a bad combination in high performance, 
high-compression, clean burning engines.

Sight Glass:
I've never heard of a sight glass blowing out...overfilled oil, perhaps? 
Have you heard that the Oilhead engines can trap oil up in the oil cooler 
and give a false "low" reading when they're really full?    It happens quite 
a bit.    When you add oil, if there is any doubt, just fill to the lowest 
point on the site glass that you can see some oil and stop.    This way, if 
oil is stuck in the oil cooler, your level will be about 75 to 85% covering 
the glass in a true reading.    If you fill to the top or nearly the top and 
there's additional oil hiding up in the cooler, you're over-full by about a 
pint. This can make for leaky block gaskets, head gaskets, and blow-by in 
the air box.    I can only see blowing the sight glass if you're running 
hard at high revs in cool to cold weather with too much oil in the engine. 
This might be enough to do it.    DEALERS over-fill constantly!!!   They put 
4 quarts of oil in the engine on a change, which is to damned much.   Then, 
you check the oil and some is up in the oil cooler, so you ad another 1/2 
quart or so and you're at a dangerous level.

Check your air box drain for oil blow-by.  There's a bayonet plug near the 
rear wheel.  Oil in there is a sure sign that the bike's being overfilled.

Question:   If you blew the site glass on the road, how long did the engine 
run without oil?  Could this have contributed to your problems here?


5 Trannie Replacements:

5????   Well, all I can say is that, if the same guy replaced the 
transmissions as adjusted your valves, you might need a new guy.    I know 
that the alignment of the transmission to the engine is critical on 
reassembly.  I've never taken on this job.  Suffice to say there's more to 
it then simply screwing in some bolts.

I also have always used BMW synthetic gear oil.  It makes the thing shift 
better and is less suceptible to damage from large amounts of heat (The CAT 
is mounted right under the transmission making for a nice little bake-off in 
slow or non-moving traffic.)  Synthetic gives me a little more peace of mind 
in this particular application and BMW synthetic seems to work well.   Yes, 
it's hidiously expensive, but you don't need much and it lasts a while.   No 
need to wait for a break-in period, beyond a few hundred miles, to use this 
stuff.  You can put it in on the first scheduled change.

I can't say as I blame you for wanted to dump your RS and get something 
else.   I'd feel the same way.

It sounds like the BMW dealer you're using is not stocked with mechanics who 
understand these bikes.   It also sounds like you don't work on the bike 
yourself.

If there is no other dealer near you, I'd go find another brand of bike. 
Try an Aprilia Falco.  (Terrific engine - I have a Mille R - and a chassis 
that can be made to work for the sport touring thing.  or a Ducati ST3 (new 
engine with good torque and easier service) or ST4 (complex valve adjustment 
procedure and dry clutch is noisy and doesn't last long)  or ST4S (stonking, 
hairy beast of an engine, Ohlins suspension, big price for bike and service, 
has a chain.  I had an ST4 for a while.  Some strong points, but not enough 
better than the RT and a little weak on lower end torque.).  or a Triumph 
Sprint ST or Sprint RS (amazingly good bikes if you don't mind the chain, 
which is less trouble then most people think. A bit of heat from the 
engines, but great engines and chassis. Styling, especially the headlights, 
need some getting used to for me.)   or   A Suzuki V-Strom (can be made into 
a nice sport touring machine, again with a chain, great V-Twin.)  or   a 
Yamaha FJ1300 (Shaft drive, continuous improvement each year.  I have a 
friend who loves his and has massaged all the kinks out.)  or  a Honda 
ST1300 (Shaft drive, a little on the heavy side, but can be made to work 
with the right goodies.) or a Honda Gold Wing (shaft drive, creamy flat 6 
engine, you'll never keep up, but you probably won't care.  Fun to ride 
anyway and you can take your S.O. because it's got the best pillion seat on 
the road.   Ground clearance is a problem until you learn to hang off in the 
turns...making U-turns in the road is problematic.  This is perhaps the 
biggest barrier to sport touring with one of these. If your road becomes 
unpaved or you make a wrong turn, it takes 3 men and a boy to change 
direction.)

All these bikes are good, but their just not BMWs yet...for me, at least, 
that still has meaning because BMWs have not turned all the way into 
Japanese made disposables yet.   I fear they may be headed in that general 
direction.  The marketing departments and stylists are beginning to take 
over.  I hope there are still some stubborn Germans in the mix to keep the 
basic quality of the machinery intact on these newer bikes.   This K12000 
appears from afar as getting very near the goals of "power, speed, 
lightness, low cost" with longevity and serviceability trailing behind 
somewhere.  This does not a good touring bike make.   BMWs have to be 
reliable long distance travellers, even the "S" versions.

That said, I have ridden an R12GS in the mountains and I have seen the 
light!   These bikes are quite exceptional and I hope they get all the 
wrinkles out by the time the RS and RT versions come out.

- -TB

>...Checked spark, fine in both cylinders, so decided dealer had
>better diagnostics. Result? Not Good...in the suspected "dead'
>cylinder, 100% leakage. Yikes. In GOOD cylinder, 80% leakage!!
>double yikes. Right side(dead) had a slice o' pie shaped chunk missing
>and unaccounted for. No sign that it'd hit the piston or cylinder wall.
>Both exhaust valves burned.

>All this on a bike that's been meticulously maintained, for both
>service and fluid intervals. What's particularly scary is that the
>leakage had gone from under 10% to failure in 14k miles, bike has 44k
>now. The wrenches guess is a combo of California gas as well as poor
>metallurgy. When I asked about this, I was told it's not uncommon;
>the 1100 RT's had some history , but never an RS. The 1150's, quite a
>bit more common.
>Triple yikes! So, think I'll fix it (don't ask what they'll charge),
>but not
>sure if I'll keep it. This has been the most capable BMW I've ever had
>in terms
>of being flexible to do the things I want a bike to do. But...after 5
>tranny replacements,
>all at BMW's expense, a sight glass blowing out and stranding me, fuel
>pump failing and
>stranding me, and now this, I'm a weeee bit nervous. Damn. Sigh.

>Thanks to all who responded originally!!


Rob

------------------------------