Throttle Valve Synchronization - Honda 1986 GoldWing GL1200A Manual

Throttle Valve Synchronization - - - - - - - - - - - - - - -
NOTE. Perform this maintenance with the engine at nor-
mal operating temperature. transmission in neutral, and
motorcycle on its center stand.
Remove the throttle body covers, right and left fairing
lower covers and Inner covers.
Remove the plugs from the intake pipes and install
vacuum gauge adapters and vacuum gauges.
Start the engine and adjust the idle speed with the throt-
tle stop screw.
Idle speed: 1000
%
1DO rpm
The difference in vacuum readings should be 40 mm
(1.6 in) Hg or less.
Turn the adjusting screw to fix any difference in vacuum
readings between the right
(# 1
and
3)
and left
(#2
and
4)
bank cylinders.
If
anyone cylinder vacuum reading is
low, check for a secondary air leak past the intake pipe.
Adjustment between the front and rear cylinders (#1 and
3,
or
#2
and
4)
are not possible. Differences in vacuum
readings between these cylinders is probably due to car-
bon build-up on the throttle valve.
To clean the throttle valves, remove the cleaning hole
plugs from the intake pipes. Remove the spark plugs.
NOTES:
• Decarbonizethe throttle valve with the highest vacuum
reading first, the lowest last.
• Use a cleaner containing a rust inhibitor.
Spray carburetor cleaner into the intake pipes while
snapping the throttle for 15-20 seconds.
With the engine stop switch OFF. crank the engine for 2
or 3 seconds.
CLEANING
HOLE PLUG
~
'/I.
Clean the spark plug hole areas. Install the spark plugs
and cleaning hole plugs.
Turn the engine switch ON and start the engine with the
throttle more than half open, then allow the engine to
Idle.
The idle speed will nse when the throttle valves on both
banks are synchronized. Adjust the speed with the
throttle stop screw and recheck synchrOnization.
If the difference in vacuum readings is still out of
specification, clean the throttle valves again. (cont'dl
~ CLOSED
-' 1/8
1/4 '... .
./
3-5