Valve Adjustment - Stephen Karlan - BMW R850 Maintenance Manual

Valve Adjustment - Stephen Karlan (Dali Meeow)
TOOLS NEEDED
newspaper (oil catcher)
med. screwdriver (pry)
compressed air
hemostat for rubber plug
5/8-in. or 17mm socket
You must start with a cold engine. Put newspaper or drain pan under the cylinder heads
to catch the oil drips. Remove alternator cover using 4mm Allen wrench. Check
alternator belt for cracks and tension and then leave cover off for valve adjustment.
Remove round black rubber timing hole plug (size of quarter) located on right side of
engine (above and to the rear of the cylinder head) by grabbing the edge of the plug
with a hemostat (medical tweezers, marijuana roach holder) and pulling or carefully pry it
out with a long screwdriver. Timing marks will be seen inside of this hole later on during
the adjustment procedure.
Remove black plastic strip ("4 Valve" imprinted on part) covering the spark plug by hand.
Remove plug wire from plug by using 2-inch long black plastic loop tool contained in
your BMW tool kit. The purpose of the black plastic loop tool is to give you a handle to
pull on that will pull the plug wire off the plug. Holding onto the loop end, point open side
toward rear of bike while hooking the tool onto the plug wire boot, then pull out to
remove the plug wire. Use compressed air to blow out plug hole before removing plug --
there will be dirt in that hole that you don't want in your cylinder !! At the very least, use a
tube or straw to direct the air and lots of lung force. Remove spark plug using tool kit
wrench. Place a pan/newspaper under the valve cover to catch the small amount of oil
that will drip out when you loosen the four valve cover Allen screws. Loosen the Allen
screws with a 6mm wrench and remove the valve cover; lightly tap if it's stuck.
With bike on centerstand and in neutral, use appropriate socket (5/8-in. or 17mm,
depending on bike) to turn the lower alternator drive pulley (and engine) clockwise.
Insert long screwdriver into either spark plug hole while turning engine over; when
screwdriver is being pushed out, start looking for timing marks. Use a small flashlight to
illuminate the flywheel marks. The marks, in order, are "Z", "S" and "OT". Center "OT"
in the timing hole opening.
Optional method #1 for moving the cylinders into place: Instead of looking at the
flywheel index marks, remove both spark plugs and put the bike on the center stand in
5th gear. Put a long screwdriver into either spark plug hole and push it against the
piston crown. Rotate the rear wheel until the screwdriver projects the maximum distance
out of the cylinder. Rock the engine by moving the rear wheel slightly back and forth to
get the piston at the very top, OT.
With OT centered, the valves on one side of the engine will "wiggle" a little bit. If they do
not "wiggle", check the valves on the opposite side of the engine. One side or the other
must wiggle. Adjust valves using 10 mm box wrench, 3mm Allen and two feeler gauges.
BMW recommends the following two feeler gauge dance step. One gauge is used to
adjust the intake (or exhaust) valve while the second feeler gauge is positioned under
the adjoining intake (or exhaust) valve to stabilize and prevent the rocker from canting.
flashlight
3, 4, 5, 6 mm T handle Allen
torque wrench
10mm box wrench
pliers
38
drain pan
plug tool
2 sets gauges
carb stix