FW: R1100 fuel injection/surging/fixes -- part 3 FW: R1100 fuel injection/surging/fixes -- part 4 Broken push rods [none] Re: FW: R1100 fuel injection/surging/fixes -- part 3 Re: Broken push rods Bosch Blue Coil Warning Re: Broken push rods Reading Spark Plugs Reading Spark Plugs Re: FW: R1100 fuel injection/surging/fixes -- part 3 Re: BMW: Cat Converter Destruction. bmw-tech-digest V1 #5
From: Rob Lentini <lentini@azstarnet.com>
Date: Wed, 20 Mar 1996 17:55:10 -0700
Subject: FW: R1100 fuel injection/surging/fixes -- part 3
Bear with me!
- ----------
> From: Rob Lentini[SMTP:lentini@azstarnet.com]
> Sent: Sunday, March 17, 1996 7:33 AM
> To: 'r1100 list'; 'bmw tech'; 'ibmwr'; 'buickcampr@aol.com'; 'jon =
diaz'; 'jim roche'; 'mick mckinnon'
Cc: 'roger austin'
> Subject: R1100 fuel injection/surging/fixes -- part 3
Part 3 of a series:
If you recall part 1 of my previous two posts on this subject, you will =
remember that the BMW Motronic data I referred to mentioned that there =
are three most-important inputs to the Motronic contol unit:
1. Engine Speed (from the Hall transmitters)
2. Top Dead Center (TDC) (also from the Hall transmitters) =09
3. Throttle Position Sensor (TPS)
The TPS is mounted on the outside of the left throttle body. It's the =
square shaped black module with a connector on its bottom side. The TPS =
is a rheostat, or variable resistor. Connected to the throttle =
butterfly, it transmits an input to the Motronic based on throttle =
opening--anywhere from idle to wide open. The Motronic compares the TPS =
to all the other sensor inputs to give the proper (we hope) engine =
management for existing conditions.
The adjustment of the TPS is very critical to engine performance =
(remember the 3 important inputs!) Adjustment is made by loosening the =
two socket head screws, the ones with blue paint on them, and rotating =
the sensor to achieve correct adjustment.
The BMW Motronic fault reader is the tool your dealer also uses to set =
the TPS. First they will clear any faults in the system. Then the =
technician will rotate the TPS until a "0" indication is flanked by two =
small "o"s. The screws are then tightened, and the adjustment rechecked =
by opening and closing the throttle. The tool does not read out the =
actual voltage from the TPS to the Motronic.
Based on empirical data from my own R1100RS and other reliable sources, =
the correct voltage range of a properly adjusted TPS will fall within =
.370 - .400 volts DC. This voltage may be measured at the TPS =
connector using a quality DVM (Digital Voltmeter). Carefully pull the =
connector boot down to expose the wires, and probe between the red/white =
wire (+) and a good ground (-) on the engine. A long needle probe, or =
use of a paper clip, will help you make contact with the pin of the =
red/white TPS wire. Turn on the ignition and be sure the engine cutoff =
switch is in the "run" position (as an MSF Instructor, I always turn my =
engine off with it :). Your DVM should now be reading the TPS output, =
and your reading should fall within .370 - .400 volts.
Now then, don't touch this adjustment just yet! =20
How is your R running? Fine? "If it ain't broke, don't fix it", is =
good advice in this case. However, for certain driveability problems =
I've found readjusting the TPS can make a big and positive difference.
Let's back up for a moment. Recall that on a cat-equipped US spec bike, =
the Cat Code Plug (CCP) "Golden Yellow" for an RS and "Rose Pink" for =
GS/R will be installed. These CCPs activate the appropriate internal =
Motronic "maps" that include inputs from the oxygen sensor (O2).
O2 sensors need to be hot to work correctly. The one's on our Rs have =
an element and a heater inside. While riding the bike, hot exhaust =
gases and the heater conspire to give the correct Lambda (oxygen) =
reading to the Motronic unit. This results in very low CO readings and =
is just what a catalytic converter likes and needs to work properly.
Here's the link to the .370 - .400 voltage: With my exhaust analyzer =
(Heathkit) hooked up, and with the engine held at mid to high RPMs, I =
measure very low CO--around 0-1%. When the engine is idling, and =
recalling the need for hot exhaust to make the O2 sensor work correctly, =
my measurement of CO increases. In this regime, the adjustment of the =
TPS may be very accurately set.
It's as simple as this: At the upper end of the spec, .400 volts, my CO =
goes up to about 2-3% and at the lower end, .370, it goes down but the =
motor doesn't idle as smoothly AND (!) tends to surge more. This is =
IMPORTANT! If everything is set up correctly (CCP, throttle body synch, =
EVERYTHING!) and the bike surges, measure your TPS voltage. I'll bet it =
will be on the low side. =20
Carrying this a bit further, I set my TPS to .450 just for grins. =
Throttle response is absolutely awesome and instantaneous! Cruise CO is =
still held to 0-1% by the O2 sensor, though idle CO increases to 3-4% or =
so. CAUTION: I'm running a non-cat Staintune. I don't know whether =
the .450 will be cat-friendly, so its YOUR call on this. Careful!
CAUTIONARY NOTE: Don't do this unless you've got the expertise. For =
driveability problems with an R under warranty, complain to your dealer. =
You MAY have a fault in the system that he can read out and fix. =20
So that's it, Motronic 101 :)
I'd like to thank the other accomplices on this project:
- - Jon Diaz, for all the phone calls, posts, and general mentoring of =
this newby. - Mick McKinnon, for being my Guinea Pig with his =
NEW R1100RT (thanks!).
- - Tom Bowman, for sharing his considerable oxygen sensor knowledge.
- - Eric King, Iron Horse Service Manager, general GOOD GUY!
I've got a few more R1100 tips, but my fingers are tired and I'm going =
riding (what a concept!). More tomorrow. =20
Robert J. (Rob) Lentini
ARCC MSF BMWMOA BMWRA AMA
2509 S. Sahuara Ave.
Tucson, AZ 85711
(520) 790-8865
'94 R1100RS
'87 K75S (sold, NOT forgotten!)
------------------------------
From: Rob Lentini <lentini@azstarnet.com>
Date: Wed, 20 Mar 1996 17:56:19 -0700
Subject: FW: R1100 fuel injection/surging/fixes -- part 4
Maybe I'm done! :)
- ----------
> From: Rob Lentini[SMTP:lentini@azstarnet.com]
> Sent: Wednesday, March 20, 1996 5:00 AM
> To: ''buickcampr@aol.com'; 'r1100 list'; 'bmw tech'; 'ibmwr'; 'jon =
diaz'; 'jim roche'; 'Rob'; 'mick mckinnon'; 'roger austin'
> Subject: R1100 fuel injection/surging/fixes -- part 4
=09
Part 4 of a (maybe) 4 part series:
Here's how to put together the preceeding three part experience I have =
had with my R1100RS. Please note that I did all my experimenting on my =
bike, an R1100RS--not a GS with different engine compression and cam =
timing.
In review, you need to be SURE that ANY driveability problems are NOT a =
result of a fault in the Motronic system. To be SURE, have your dealer =
read and correct any faults he detects. Your WARRANTY covers this, as =
do EPA and DOT regulations. =20
Assuming a clean bill of health, CONSIDER the following mods:
1. Advanced Ignition Timing (similar to my K75 article on the web)
2. Valve Lash Increase
3. Super-Accurate Throttle Body Synch
1. Advanced Ignition Timing:=20
Most manufacturers set the ignition timing for the typical vehicle with =
poor fuel quality in mind. Performance gains may be achieved by =
REASONABLE increases in initial advance. The R1100 is no exception.
Assuming you are NOT experiencing ANY pinging or detonation, you can =
easily advance the ignition timing by about 3 degrees. Here's how to do =
it:
- Remove the small rubber cover on the clutch bellhousing (just inside =
the right throttle body).
- Remove the black cover on the front of the engine. This covers the =
alternator drive pulleys/belt.
- Notice on the lower (crankshaft) pulley that the three timing plate =
securing screw are exposed, and that the timing plate (which the Hall =
transmitters are mounted on) can slide CW and CCW in three slotted =
holes.
- Put the tranny in 5th gear and, while observing the flywheel with a =
good flashlight, move the rear wheel to rotate the engine. You will be =
looking for "OT" (top dead center), "Z" (full advance) and "S" (the 6 =
degree initial advance mark).
- Warm the engine and observe, with a timing light, where initial =
advance is taking place. With the engine at 1000 RPM or less, the =
advance will be very close to "S". Turn off the motor, loosen the three =
screws holding the Hall transmitter plate, and tap the plate in a CCW =
direction from the front to the end of slot travel. Tighten down the =
three screws and recheck the timing. Be SURE the idle RPM is 1000 or =
less! If your R1100 is like mine, the timing will be advanced 50% =
further than the "OT" to "S" mark, for about 9 degrees of initial =
advance. If so, put everything back together and, if during your test =
ride you detect no noticeable detonation, you are in business.
2. Valve Lash Increase:=20
If you are like me, try this. I like low and mid-range driveability =
and throttle response. My R1100RS would not idle for several minutes on =
cold mornings until I increased valve lash. This FIXED the problem, and =
I've lost no discernable top-end power.
Set the valves COLD from/to:
Intake: Spec: .006" to: .010"
Exhaust: Spec: .012" to: .014"
Your idle and throttle response will be MUCH smoother. Increase in =
valve noise is nominal. Valves will run cooler.
3. Super-Accurate Throttle Body Synch: (an extention of Diaz' method)
Many R11 riders have reported the benefits of being anal retentive in =
the synching of the two throttle bodies. Surging can be dramatically =
reduced just by synching the throttle bodies VERY precisely. Here' how =
to do it:
- - Buy/borrow a mercury manometer. Vacuum gages just don't hack it.
- - Loosen the crossover synch cable for the right throttle body to assure =
some free play.
- - Loosen the throttle cable to assure some free play.
- - Install the mercury manometer
- - Close BOTH brass air bypass screws on the throttle bodies. Just seat =
them, don't over-tighten!
- - Aim a medium to large fan at the front of the engine.
- - Warm the engine for at least 15 minutes.
- - Check mercury levels. Adjust one or both of the FORBIDDEN throttle =
------------------------------
From: David Crisp <davidc@ist.flinders.edu.au>
Date: Fri, 22 Mar 1996 03:13:03 +1030
Subject: Broken push rods
Hi all,
My friends R75/5 has just stopped working. The reason being that the end of
a push rod snapped off. It was a clean break just below the end which fits
into the rocker arm. The broken piece fell into the bottom of the rocker
cover and there seems to be no damage done.
However, there also seems to be no reason for the push rod to break. Our best
guess is that it was natural wear and tear and this is to be expected on
a bike which has done over 100,000 miles. Is our guess sensible?
Can we fix it by simply buying a new push rod and putting it in? Or do you
need to replace the parts it fits into as well? And what about the other
rods? Can a broken push rod cause any serious damage?
Thanks,
David Crisp.
Adelaide, Australia.
------------------------------
From: Ned Thaxton Beck <ntbeck@lx13.tx.ncsu.edu>
Date: Thu, 21 Mar 1996 10:54:51 -0500
Subject: [none]
http://www.bmw.ca/resource/share/saver.htm, l ( )
At daytona my starter began to act up. Sometimes when starting it makes a
terrible noise exactly like when you hit the starter on a bike or car while it
is already running. It sounds like the starter gear is not meshing wiht the
flywheel or something. I thought it may be a fake neutral phenomenon with the
transmission so i began pulling in the clutch to start the bike. i also tried
starting the bike with the clutch lever pulled in and the tranny in 1st or
second gear. Sommetimes all of the methods would work but never consisitently
and thus i could not discern what the problem was. Then suddenly the starter
would decide it wanted the behave and start the bike for no apparent reason.
When gassing up and such, sometimes the bike would start just fine but usually
not. if anyone knows the problem here please let me know asap....the battery is
well charged and the starter components spec out. The flywheel gear is not worn
( i have not had a chance to check the starter gear simce the trip).any help
and advice would be greatly appreciated!!
Please email me direct
Ned T. Beck
- --
ntbeck@tx.ncsu.edu
++++++++++++++++++++++++++++++++
------------------------------
From: joe@mpd.tandem.com (Joe Senner)
Date: Thu, 21 Mar 1996 10:50:55 -0600 (CST)
Subject: Re: FW: R1100 fuel injection/surging/fixes -- part 3
]O2 sensors need to be hot to work correctly. The one's on our Rs have =
]an element and a heater inside. While riding the bike, hot exhaust =
]gases and the heater conspire to give the correct Lambda (oxygen) =
...
]recalling the need for hot exhaust to make the O2 sensor work correctly, =
]my measurement of CO increases. In this regime, the adjustment of the =
I would offer that the exhaust gasses have no effect on the sensor on the R11
given its location relative to operating temperature. The sensor ceramic
has to be within just a few inches of the combustion chamber in order to
gain enough heat from the exhaust gases to operate normally. if it's not
screwed into the head or you sometimes run below 5 grand, it's gonna need
a heater :-)
an engine pushing 1.5 liters through a 1.25inch diameter pipe with a sensor
located 6 inches from the chamber still requires a heater.
- --
Joe Senner
Diazonimbus Cloud Watchers Society
------------------------------
From: tchilder@sybase.com (Tom Childers)
Date: Thu, 21 Mar 1996 09:32:05 -0800
Subject: Re: Broken push rods
David Crisp asks:
>Hi all,
>
>My friends R75/5 has just stopped working. The reason being that the end of
>a push rod snapped off. It was a clean break just below the end which fits
>into the rocker arm. The broken piece fell into the bottom of the rocker
>cover and there seems to be no damage done.
>
>However, there also seems to be no reason for the push rod to break. Our best
>guess is that it was natural wear and tear and this is to be expected on
>a bike which has done over 100,000 miles. Is our guess sensible?
>
>Can we fix it by simply buying a new push rod and putting it in? Or do you
>need to replace the parts it fits into as well? And what about the other
>rods? Can a broken push rod cause any serious damage?
It isn't normal to break pushrods, but after 100,000 miles, I wouldn't
worry about it much. It sounds to me like there is no damage (it is
generally difficult for a broken pushrod to damage anything, except
possibly the rocker arm). Fitting a new rod should not be a problem.
Ideally, you replace the tappet/cam follower at the same time, but the
tappet and cam are nicely worn into each other, I would leave the tappet in
place.
I *would* check the oil delivery to the rocker arms, and make sure that
there is no binding that is putting stress on the pushrods. I would also
consider upgrading to later model pushrods, which are somewhat lighter, if
they are the proper length and fit the rockers okay.
- -tdc
------------------------------
From: "Malcolm A. Meyn" <tmeyn@ag.arizona.edu>
Date: Thu, 21 Mar 1996 14:33:04 -0700 (MST)
Subject: Bosch Blue Coil Warning
Recently there was some talk on the list about using Bosch Blue coils as
replacements in airhead R's. I've been running mine now for about a
month and they've worked fine. Recently, though, myself and another
president, who also had recently installed Blues, had the unfortunate
experience of shorting out our ignition systems on our bikes.
The problem arises from the size of the terminals on the Blues, they are
larger than on the stock. Due to their size it is very easy to pinch one
of the many brown wire (which attach to the frame at the mount of the left
coil) grounds between the tank and the terminal of the left coil. The
result is a smoking headlight shell and starter switch.
The fix is easy, just bend all the tabs of the coil terminal inwards
towards each other. You could even cut off some of the unused tabs if
you want.
Just a note to help others avoid what appears to be a small risk on
installing Bosch Blue coils.
Best,
Tony Meyn
'76 R90S
------------------------------
From: robert frasier <o9790174@wsunix.wsu.edu>
Date: Thu, 21 Mar 1996 13:52:13 -0800 (PST)
Subject: Re: Broken push rods
Broken push rods are not really "normal" wear and tear. However, if your
friend routinely runs his bike at or near redline, it is possible that
fatigue got to what would be an otherwise acceptable unit.
You did not mention whether your friends bike is stock. If the valve
springs have been shimmed or replaced with stiffer units, this will
increase the load on the pushrod. It will also usually show up as
accelerated wear on the lifters and cam though.
Examine the rod closely to see if there is evidence of the rod contacting
the head. This of course will show as shiny or rubbed away areas on the
rod. If this is the case, and it is more than just a little polishing
from occasional contact, there is likely something wrong with the way the
geometry of the head is set up. Someone in the past may have done
something to alter the relationship between the rocker shafts,
valvestems, etc. I have seen these types of failures on racing VW
engines where the valves had been enlarged, and the new, bigger valve
seats let the new, bigger valves sit up just a tad closer to the rocker
than they should. That would screw up the geometry just enough so that
the pushrods were a little closer than normal to the heads, and when they
flexed at high revs, would contact the head hard enough to do damage.
It is also possible that your friend just got a wimpy pushrod. Replace
it, and ride on.
I would have you send it to me, and I could give you an "expert" opinion
of how it failed, except that you'r in Aus. and I'm in the US. And, I am
2 years behind on the failure analysis of the cam, lifters, and rockers
of Sven-Erik Tibourg's Krauser 4 valve head stuff.
Regards
Bob Frasier
------------------------------
From: Scott_H._Baxter@notes.up.com (Scott H. Baxter)
Date: Thu, 21 Mar 1996 17:20:51 -0600
Subject: Reading Spark Plugs
I've got a stock 1981 R100 with 38K on the odometer that just had a new valve,
valve seat, and ring job. I'm arguing with my BMW dealer now about my spark
plugs. The plugs are Bosch units with the recommended heat range. Here is
what they look like:
RIGHT CYLINDER
1. dry, shiny black coating on negative electrode, porcelain insulator, and
positive electrode facing the intake valve and covering half of the insulator
and electrodes.
2. dry, velvety black coating all around the plug's base (bottom of threads)
with no variation in color
3. porcelain insulator facing the exhaust valve is clean and white as new.
No black specks, just white white for around 180 degrees facing the exhaust
valve.
LEFT CYLINDER
The left cylinder has the same dry shiny black stripe on the plug's intake
side covering half the porcelain insulator and the same soot color and texture
on the spark plug base, only the porcelain insulator on the exhaust side is a
dry grayish tan I normally associate with a good combustion chamber
environment.
Plug color was NOT checked in a careful manner. I rode the bike in town
for an hour (mix of highway, street, stop, go) and pulled the plugs. I shall
reexamine the plugs by putting in a new pair, riding a half hour on the
highway at 4k RPM (which my dealer wants me to do) then pull the plugs.
I basically need to know what an airhead plug should look like. I can
see that the black stripe is likely the result of cool fuel/air hitting a very
hot insulator but I don't know why it doesn't burn off. I'm not used to this
at all. I don't like the white insulator either. The right cylinder had
significant valve problems which resulted in the overhaul and had this plug
condition when I bought it. I don't want this to shorten engine life through
excessive combustion chamber heat. I'm also not used to plugs that have such
different insulator colors. My BSAs, Triumphs, and Nortons had better color
matching, but then again I fiddled with the Amals a lot...
To wrap up, I need to know if I am worrying about nothing or if there is
room for improvement. Given the money I spent with these people I am
interested in getting the bike right, not just better than it was. My
appreciation in advance to all who respond...
------------------------------
From: Scott_H._Baxter@notes.up.com (Scott H. Baxter)
Date: Thu, 21 Mar 1996 17:20:51 -0600
Subject: Reading Spark Plugs
I've got a stock 1981 R100 with 38K on the odometer that just had a new valve,
valve seat, and ring job. I'm arguing with my BMW dealer now about my spark
plugs. The plugs are Bosch units with the recommended heat range. Here is
what they look like:
RIGHT CYLINDER
1. dry, shiny black coating on negative electrode, porcelain insulator, and
positive electrode facing the intake valve and covering half of the insulator
and electrodes.
2. dry, velvety black coating all around the plug's base (bottom of threads)
with no variation in color
3. porcelain insulator facing the exhaust valve is clean and white as new.
No black specks, just white white for around 180 degrees facing the exhaust
valve.
LEFT CYLINDER
The left cylinder has the same dry shiny black stripe on the plug's intake
side covering half the porcelain insulator and the same soot color and texture
on the spark plug base, only the porcelain insulator on the exhaust side is a
dry grayish tan I normally associate with a good combustion chamber
environment.
Plug color was NOT checked in a careful manner. I rode the bike in town
for an hour (mix of highway, street, stop, go) and pulled the plugs. I shall
reexamine the plugs by putting in a new pair, riding a half hour on the
highway at 4k RPM (which my dealer wants me to do) then pull the plugs.
I basically need to know what an airhead plug should look like. I can
see that the black stripe is likely the result of cool fuel/air hitting a very
hot insulator but I don't know why it doesn't burn off. I'm not used to this
at all. I don't like the white insulator either. The right cylinder had
significant valve problems which resulted in the overhaul and had this plug
condition when I bought it. I don't want this to shorten engine life through
excessive combustion chamber heat. I'm also not used to plugs that have such
different insulator colors. My BSAs, Triumphs, and Nortons had better color
matching, but then again I fiddled with the Amals a lot...
To wrap up, I need to know if I am worrying about nothing or if there is
room for improvement. Given the money I spent with these people I am
interested in getting the bike right, not just better than it was. My
appreciation in advance to all who respond...
------------------------------
From: Brian Curry <bmwbrian@voicenet.com>
Date: Thu, 21 Mar 1996 20:39:43 -0500
Subject: Re: FW: R1100 fuel injection/surging/fixes -- part 3
At 10:50 AM 3/21/96 -0600, Joe Senner wrote:
>]O2 sensors need to be hot to work correctly. The one's on our Rs have =
>]an element and a heater inside. While riding the bike, hot exhaust =
>]gases and the heater conspire to give the correct Lambda (oxygen) =
>...
>]recalling the need for hot exhaust to make the O2 sensor work correctly, =
>]my measurement of CO increases. In this regime, the adjustment of the =
>
>I would offer that the exhaust gasses have no effect on the sensor on the R11
>given its location relative to operating temperature. The sensor ceramic
>has to be within just a few inches of the combustion chamber in order to
>gain enough heat from the exhaust gases to operate normally. if it's not
>screwed into the head or you sometimes run below 5 grand, it's gonna need
>a heater :-)
>
>an engine pushing 1.5 liters through a 1.25inch diameter pipe with a sensor
>located 6 inches from the chamber still requires a heater.
The original O2 sensors did not have heaters.
>From the Bently book on Bosch Fuel Injection, the sensor needs to be above
575 degrees F (300 degrees C) to operate. Based on accidental burns :( the
exhaust may just be above that a decent amount to time. (I could be wrong
here at real cold temps and low engine speeds.) The book also noted that
without a heater, the sensor could take 90-120 seconds to reach operating
temps. With the heater it takes 10-15 seconds. This is improves
driveability and emissions.
For motorcycle applications, with thin wall headers in the great outdoors, a
heater is simple insurance that the sensor will be at "operating" temperature.
Brian Curry, 1990 Blue K75RTs both coasts, Chester Springs, PA, USA
K-Whiner #21, BOOF #38, OSP #7, "VI,CE"
BMWMOA#4578, BMWRA#12296, AMA#725653, USCA#078, PE-029523-E, N3IYL
IDN-A force for good in the world. All of the good, none of the bad.
------------------------------
From: mick@westworld.com (Mick McKinnon)
Date: Thu, 21 Mar 1996 18:46:15 -0800
Subject: Re: BMW: Cat Converter Destruction.
>At 10:24 AM 3/21/96 -0800, Mick McKinnon wrote:
>>Brian,
>> No expert here.....My educated opinion however, is that the excess
>>heat AND hydrocarbons will damage the coating of the monolith-style
>>CAT on our bikes....eventually...it could take years. If you keep your
>>bike adjusted properly, no problem....if you sometimes neglect it, then
>>you CAN damage the CAT but it'll take a while.
>
>And Brian asks:
>
>Can you elaborate what a "monolith-style CAT" is. In my cage's cat is lots
>of little wires in layers strung 90 degrees to each other. I can look
>throught the cage's CAT. Sounds like the bikes is different somehow.
>
Here goes......
"A catalytic converter with metal monolith is integrated into the exhaust
system of the R1100 RS. The catalytically active precious metals, platinum,
palladium and rhodium are applied to this metal monolith. Platinum and
palladium accelerate the oxidation of hydro-carbons and carbon monoxide,
rhodium accelerates the reduction of oxides of nitrogen. The Motronic system
with adaptive lambda control constantly ensures that the engine is operated
on a stoichiometric mixture of lambda = 1. Only when lambda has the value
1 does the three-way catalytic converter achieve its optimum rate of
conversion."
This description is right out of a tech article from BMW. It's like a BIG
screen
that is wide open towards the gas flow. Unlike the old car Cats that were
like eggcrates and tended to clog and become a restrictor in the exhaust
system. Some of the early 80's Fords had this problem and would hardly
run once the Cats were destroyed by either a very rich mixture (thanks to the
Variable Venturi Carburetors that would run full rich when their main vacuum
diaphragms would rupture). Running with a couple of dead plugs could do
this too....or using leaded fuel...etc. etc.
Mick
Mick, Simi Valley, CA, USA, North America, Earth, Solar System, Milky
Way,Universe
___________________________________________________________________
'93 K1100LT..Quick Trips! 3-Flags #76 K11LT_Mick@Vnet.IBM.Com
'96 R1100RT.....Twisties! MOA#57053 RA#28302 mick@Westworld.Com
'83 R100RT 60th Aniv. Edition..Has been adopted by a very nice family in Berkley
___________________________________________________________________
------------------------------
From: "Timothy C. Bond" <73312.1370@compuserve.com>
Date: 21 Mar 96 12:45:37 EST
Subject: bmw-tech-digest V1 #5
>How wide are or should the contact ring between the valves and the seats been.
Whats the max. value. <
.060" is a generic seat size that both seals and heat dissipates. Of course,
three angle at least after this.
Put your finger over the valve guide and pull the valve out fast. If it
doesn't go "pop" put new ones in, really. This will tell you if you have more
than .001" play.
_______________________________________________
http://ourworld.compuserve.com/homepages/WireWheels
------------------------------
End of bmw-tech-digest V1 #6
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