I just did the throttle sinc myself....

from the instructions on this site here...
www.fjrtech.com/getdbitem.cfm?item=21

and reading the manual, you shouldn't be adjusting the butterflies at all....

Quote from the manual....
SYNCHRONIZING THE THROTTLE BODIES ADJ
7. Measure:
engine idling speed
Out of specification Adjust.
Refer to ADJUSTING THE ENGINE
IDLING SPEED.
Engine idling speed
1,000 ~ 1,100 r/min
8. Adjust:
throttle body synchronization
tttttttttttttttttttttttttttttttt
a. With throttle body #3 as standard, adjust
throttle bodies #1, #2, and #4 using the air
screw 1.
NOTE:
@
After each step, rev the engine two or three
times, each time for less than a second, and
check the synchronization again.
If the air screw is removed, turn the screw 3/4
turn in and be sure to synchronize the throttle
body.
CAUTION:
Do not use the throttle valve adjusting screws
to adjust the throttle body synchronization.

NOTE:
@
The difference in vacuum pressure between
two throttle bodies should not exceed 1.33 kPa
(10 mm Hg).
ssssssssssssssssssssssssssssssss
9. Measure:
engine idling speed
Out of specification Adjust.
Make sure that the vacuum pressure is
within specification.
10.Stop the engine and remove the measuring
equipment.
Carburetor angle driver
90890-03158
Vacuum pressure at engine idling
speed
28.9 ~ 36.8 kPa
(220 ~ 280 mm Hg)

not sure where you are getting your info, but I would like to read it myself to see what your looking at..

I was under the impression that you do this all at idle...
1000 to 1100 rpm's I did mine and was quick and easy...
25 mins all back together...

Warp