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TECH
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Checking Valve
Clearance on a K1100LT
By Mike Nolan
After all the horrible
stories that I have heard about folks getting surprised when they take
their bikes in for a valve adjustment, my curiosity got the best of me
and I just had to know how many of my valves where out
of adjustment.
If you have recently
had a valve adjustment done and can
send me information about the cost of the work, or use the mail link
at the bottom of the page.
Table
of Contents
Tools and Preparation
- Tools
- #2 Phillips
Screw Driver
- Small regular
screw driver or stiff wire
- 13mm socket
- 10mm socket
- 13mm open or
boxed wrench
- Extensions
- 5mm hex
- 6mm hex
- Feeler gauge
set
Here's
a conversion table. Make sure your set
contains the range below. Some cheap sets do not.
- Gasket Sealer
- Rags
- Cardboard or
plastic for the floor
- Preparation
- The adjustment
must be done stone cold. I believe the manual says 95F maximum.
- Bryan Lally
- Haynes says
the maximum head temperature is 68 degrees Fahrenheit. I think this
is unrealistic. This would mean you could not set the valves in
many areas of the US during a summer day. Clymer's says maximum
allowable cylinder head temperature is 90 degrees Fahrenheit and
this sounds about right. - Brian Curry
- After the last
ride before I plan on checking the valves, as I park the bike, I
pull into the garage and turn the engine off. Then I lean the bike
to the right and hold it for 30 seconds or so. As far to the right
and for as long as I can manage. Then I put it on the center stand
without putting it on the sidestand or leaning it to the left. This
gets almost all the oil out of the valve cover, reducing the dripping
mess considerably. - Bryan Lally
Stripping
Down to the Valve Cover
Skip This Section go to Valve Cover Removal for
other 16 Valve K's
- Remove the left
side body panel cover over the fuse area.
- Rock the rear
of the cover while pulling out, to pull it off the rear pin.
- Slide your
hand up under the center of the cover, palm toward you, until you
can feel the attachment point of the little arm which is bonded
to the cover and exert pressure with your finger tips, away from
the bike to pop the yoke away from the mount.
Once
you have seen he rear of this cover, you will understand why so
many of them have been broken, and why it is necessary to be careful
with them.
- Pull the cover
out, then to the rear to remove it.
- Remove the left
side panel and fuel gauge.
- Remove the
single machine screw in the center of the panel.
- Remove the
two screws inside the radio cover latch area.
- Pull off the
cover and unplug the fuel gauge wire.
- Remove the radio
pocket
Don't
remove the radio out of the pocket with the pair of "forks". It's
much easier to spring the whole radio chassis out of the pocket, then
remove the pocket itself. Also, there is no need to re-enter the radio
code.
- Spring the
clips through the three, 4mm round holes. The three holes are on
the outer facing of the radio flange. (stiff wire, or small screw
driver)
- The holes are
at 12, 9, and 6 "o'clock"
- Pull the radio
up and place it on a pad on the handle bars covering the key area
and switches.
- Remove the
two phillips screws on the front inside of the pocket, and raise
the pocket up.
- Put the radio
back in the pocket and lay the pocket holding the radio back up
on the padded area.
- Tie it down
with a bungie. Mine almost slid off.
- Remove the left
side crash bar. (13mm socket, 13mm open or boxed end wrench)
- Pull out on
the plastic cap in the end of the upper mount tube.
- Remove the
13mm nut inside the tube. You will need a deep socket or an extension
to reach into the tube.
- Remove the
two 13mm nuts on the lower studs. The rear one has a braided ground
strap. Be careful not twist the strap and break it. (Don't ask me
how I know this)
- Pull the crash
bar off the three mount studs.
- Remove the left
side lower fairing.
It
is helpful in this step to figure some way to remember which screw
goes where. I wrote a description of the screws on paper, as well
as laying them out on the floor in the order and shape of the lower
fairing, so that they would not get mixed up. There are several
different types and lengths of screws holding the lower fairing on.
- Remove the
machine screw from the back, inside of the fuel gauge area.
- Remove the
screw from under the rubber mount at the lower rear.
- Remove two
screws from lower front.
- Remove four
screws from the backside, behind the fork tubes, where the radiator
grill is located
- While supporting
the lower fairing with one hand, unscrew the three anodized screws
under the radio pocket area.
The
fairing will fall off into your hand when you loosen the last
of these three screws, so catch it!
- Remove the 10mm
bolt securing the mount arm on the rear, top of the head. This arm accepts
two screws via body clips, below the fuel gauge. Don't let the clips
get away.
Valve
Cover Removal
The BMW
manual strongly tells you NOT to remove the spark plugs before
checking valve clearance. The reasoning is that carbon from the plugs
or threads could wedge under the valve seats and give a false reading.
- Remove the four
hex bolts holding the spark plug cover. (5mm Hex Wrench)
- Stuff a rag in
the area of the spark plug wire caps. This will catch any oil that drains
down from the upper, intake valve side of the head casting.
- Loosen eleven round
headed hex valve cover bolts. Some will come out all the way, while
others will remain in the cover. (6mm Hex Wrench)
- Place a pan or
some cardboard under the valve cover.
- Bump the cover
with your fist, while pulling it away from the head.
- The valve cover
should almost drop off when you remove the bolts. Use a soft rubber
or plastic mallet if it will not. Or tap it using the wooden handle
of a conventional hammer. If it is stuck, make sure you have all the
bolts off, you have probably missed one. (DAHIK) - Brian Curry
- Wiggle the cover
off the head being careful not to tear the rubber gasket.
- When you do this,
it is good to have a spare set of new valve cover gaskets available.
This scares the old gaskets into submission and they will not hurt themselves
and need replacement. ;);) - Brian Curry
- Locate the grounding
spring on one of the posts inside the cover area. It should stay on
the post, but it you don't see it, find it.
Checking
Intake Valve Clearance
The
Top Cam
- Shift the transmission
into 5th gear.
- Get a paper and
pencil. Make a drawing on the paper to correspond with the valves so
that you can write down two numbers for each valve.
- Disconnect the
coil wire at the distributor cap and ground it to the engine somewhere.
- Mick McKinnon
- Rotate the rear
wheel counter clockwise (as if the bike was traveling forward) until
the one set of lobes points directly away from the buckets.
- The valve stems
are splayed outwards away from the sparkplug cavity. So when the cam
lobe is 180 degrees out (opposite) the valve stem, (the measurement
position) it will be pointed somewhat up or down and not simply "out".
- Brian Curry
- Starting with .127mm,
slide the feeler gauges between the cam lobe and the bucket until you
find the size that will not go under the cam lobe.
- I found the feeler
gauges can be inserted to check the clearance most easily from the spark
plug cavity direction. - Brian Curry
- Write down the
two sizes for each lobe, the one that will go under, and the one that
won't go under.
If
.127mm will not slide under a lobe, the valve is tight, use successively
smaller ones until you find one that does go under. The clearances
for the intake valves should be between .150mm and .200mm.
- Continue rotating
the rear wheel to bring up a set of intake valves, and then measure
to get the two reading for each of the eight valves.
- When you finish
you should have eight pairs of numbers. Here are mine.
| 1A
| 1B
| 2A
| 2B
| 3A
| 3B
| 4A
| 4B
|
YES
| .152
| .152
| .152
| .152
| .178
| .127
| .152
| .152
|
NO
| .178
| .178
| .178
| .178
| .203
| .152
| .178
| .178
|
- Your valve clearance
is somewhere between these two numbers.
- By looking at the
above numbers, numbers 3A and 3B could be in need of adjustment. 3A
could be loose and 3B could be tight. So far, so good, but exhaust valves
may bring some bad news.
Table
of Contents
Checking
Exhaust Valve Clearance
The Bottom Cam
- Follow the steps
for the intake valves, except the clearance for exhaust valves is .200mm
to .300mm
| 1A
| 1B
| 2A
| 2B
| 3A
| 3B
| 4A
| 4B
|
YES
| .229
| .178
| .254
| .229
| .305
| .279
| .279
| .330
|
NO
| .254
| .203
| .279
| .254
| .330
| .305
| .305
| .356
|
- Looking at the
above, number 1B is tight, 3A and 4B are loose.
Bad news.
Three exhaust valve buckets need to be changed. With the two intakes that
are close, I need a total of 5 buckets. At $22 each, I need $110 worth
of buckets.
To change the buckets,
the cams have to be removed and it takes several special tools to do
this. I don't know how many shop hours it takes to do the adjustment,
but after I take the bike in, I'll add the info to this page.
Reassembly
- Clean the valve
cover and the head surface completely of oil. I used kerosene and mineral
spirits on the valve cover, because it is painted and my standard solvent
for gasket prep, lacquer thinner, might have taken the finnish off the
cover. I wiped down the head surface with lacquer thinner .
- Clean the rubber
gasket of sealant. It took me over an hour to remove the sealant off
the gasket. The manual says to use Threebond 1209, which I could not
find, so I used Permatex high temp black sealant.
- Place the cover,
gasket side up, on the ground or a table and insert the gasket into
the cover. The gasket has a "T" shaped cross section, and the base of
the "T" inserts into the valve cover.
- Align the index
marks in the "half moon" projections in the rear of the cover, with
the index marks on the gasket.
- Don't use sealant
between the gasket and the cover.
- Work the gasket
into the channel toward the front end of the cover.
- Place a light coat
of sealant over the "half moon" projections, and be sure to cover the
corner where the projections connect with the flat part of the gasket.
(I spooged the whole thing)
- Make sure the grounding
spring is on the post and put the cover back on the head.
- Insert the eleven
round head hex bolts and run them down, but don't tighten them.(6mm
Hex Wrench)
- Starting from the
center, and working in a criss-cross pattern, tighten the bolt to 8
newton-meters. (Which is not much, so have the right torque wrench)
The valve cover
gasket compression is preset. It cannot be "snugged down" greater
than the amount allowed by the *shouldered* bolts. (The shoulder,
not the gasket causes the resistant to tightening.) When they are
"snug" they are as tight as they are going to be. Tightening them
more will not squoosh the gasket. It will pull the mounting threads
out of the cam shaft pillow blocks. This is not a good thing. If you
pull the threads out, it is new head time, as the cam shaft pillow
blocks are linebored. IMO, I think the "factory torque value" for
these fasteners is too high. If the cover is leaking, figure out what
is caught in it, or get a new one, or try putting some silicone caulk/seal
on it. - Brian Curry
- Follow the reverse
order of disassembly until you have it all back together.
- Let the bike sit
overnight for the sealant to cure.
- Call Pat Roddy
and meet him at the local Harley Dealer.
Comments
From Others
Scott Lee
- Gasket sealer
goes at the upper-left corner and near the half-moon gaskets.
- Grave warnings
not to over-torque the valve-cover retaining bolts are in order. The
result of stripping out a valve cover bolt are:
- Leaky gasket
if bolt strip not repaired.
- Helicoil/keyinsert
to repair, if repairable.
- NEW HEAD
if not repairable, as the cam retaining blocks/saddles are aligned
bored with the head and are NOT interchangeable.
- The way that
works for me (no leaks) is to use a 1/4 inch drive ratchet (small
handle, less torque transmitted, better "feel"), and "tighten firmly,
but not too firmly" after feeling the bolt bottom out. Same method
(and warnings..) for the crankcase cover apply, BTW. Even though I
am a firm believer in using a torque wrench, the cost/availability
of quality torque wrenches that read that low is questionable, and
if the torque wrench reads wrong or doesn't "click", you can be in
a heap of trouble quickly, especially the novice mechanics that will
be using the FAQ as guidance (remember your audience).
- Your instructions
are obviously for a 16 valve LT. Leaving out the bodywork removal
tips would probably be OK.
- Metric measurements-MANY
people use english unit feeler gauges, so including those numbers
would probably be a good idea.
- The gaskets are
good for 2 or 3 uses, then will need replacing, WITH the rubber buttons
on the bolts and half-moons. Rubber buttons are best removed from
the bolts with a pair of "diagonal wire cutters" (AKA dikes).
- Well, how do
you adjust the valves?? Several expensive special tools to remove/replace
the cams, etc.?? What exactly does it take? If its' $150.00 in special
tools, and a 3 hour labor hit, the tools pay for themselves the first
use (assuming zero value for your time). Shim measurement and the
tools required (micrometer vs. dial calipers, etc.) might also be
a discussion area...
Graham Smith
- Most BMW dealers
have an EXCHANGE service for the shims. New shims here are AUD$30.00,
exchange is $8.00. I needed 8 shims after shuffling around what I
had because ALL of my valves had been lapped in after the head service.
- "In the know"
tip #1: If you have to take the head off, you can check the clearances
BEFORE you put the head back on the bike. This way if you have a clearance
that's too small, you can remove the valve and linish off a bit of
the valve stem top until you have correct clearance, saving you a
shim.
- I didn't think
I needed ANY special tools. Albeit I have a well stocked tool box,
but I didn't need anything more special that a GOOD set of feeler
gauges and a torque wrench.
- I have been advised
by "People in the know" NOT to use any sealant on the rubber gaskets
except for the "T" or the "Cross" as it is known, where the timing
case meets the head, and a little on the 1/2 moon parts. Otherwise
NO SEALANT AT ALL is required. Suggested sealant is Wurth super silicone.
(The RED stuff)
- Warning - Do
NOT do any of this if you are not familiar with timing gear and it's
assembly or disassembly. If you get it wrong you will have valves
putting holes in pistons where there were none before.
- You have to remove
the cams to change a shim. The "Special Tool" and "Cams in head" replacement
is for K100 ONLY. To remove the cams, you have to remove the crankcase
cover and timing chain cover. Turn engine over until you are at firing
position TDC number 1 cyl. Then remove timing chain tensioner and
cam sprockets. This will allow you to remove all the cam retainers
& cams and start to change shims. Use a magnet to remove the shims
from their guides. Use Engine Assembly Grease (MolybdinumDisulphide+Graphite)
smeared around the OUTSIDE of the shim when installing and also all
over all cam wear surfaces and head bearing surfaces. Install cams,
attach sprockets, install tensioner, turn engine over by hand a few
times and repeat entire process until you run out of patience or correct
clearance shims and give it away until next weekend. At that rate
it's taken me 5 weeks to put the covers back on...
Richard Cliatt
- wrench @ Global Imports, Atlanta
- Valve adjusting
buckets should not be swapped around or re-used because of the wear
pattern develops on the bucket.
- Throttle bodies
should be balanced after a valve adjustment because changing the amount
of opening of the valve, changes the volume of air flowing through
them.
Brian Curry
- I use a "Go-No
Go" measurement technique. I find it easier than knowing I have the
correct amount of feeler gauge drag, or what a "firm push/pull" is.
For a measurement of 0.007" I would use three gauges: 0.006", 0.007",
0.008". The 0.006 should go through with virtually no drag. The 0.007
should go through with some drag. the 0.008" should not go through
at all. The result is that the clearance is 0.007" This has worked
fine for me for over 200K miles of R bike service. In a "measurement
mode" I find the gauge that is blocked. I then check that the next
lower gauge thickness will push through and the two thicknesses lower
gauge passes easily. So, if 0.010" is blocked, 0.009" pushes through,
and 0.008" passes easily, the clearance is 0.009".
Conversion
Table
- inch - mm
- .005 - .127
- .006 - .152
- .007 - .178
- .008 - .203
- .009 - .229
- .010 - .254
- .011 - .279
- .012 - .305
- .013 - .330
- .014 - .356
Back to Tools
and Preparation section
Table of Contents
Comments,
Additions, and Corrections to:
mdnolan@concentric.net
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