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© 2011 ICS- Blount Inc Specifications and pricing are subject to change without notice. P/N 525747 REV12Sep2012
680GC SERVICE MANUAL
23.5
Start the saw and warm up the engine.
23.6
With a tachometer check the saw rpm, with a
bar and no chain.
Idle = 3,000 ± 200 rpm.
If the idle rpm does not fall into this range,
adjust the T screw, clockwise to raise rpm,
counterclockwise to lower rpm.
23.9
When the carburetor is adjusted correctly,
set the limiter caps securely onto the needle
screws with a straight blade screwdriver.
23.7
With a tachometer check the saw full throttle
rpm, with no bar and chain:
Target:= 11,500 ± 500 rpm
23.8
If the full throttle falls below this range, turn
the H screw in (clockwise) 1/16th of a turn at
a time.
A. Pulse the throttle to help stablize the
system.
Do not hold the saw at max rpm for
more than 5 seconds or cylinder damage
could occur.
23. CARBURETOR TUNING
