Honda GX 120 Tech Manual page 12

E. Ignition coil or its position, other than air gap, may not be altered in any way. Coil mounting bolts must
be stock and cannot be altered in any way to advance or retard timing. Coil attaching bolts will be stock
6mm cap screw l-1/16" long. There can be no more than 3/8" of unthreaded portion of bolt that does not
measure 0.230" diameter. This restricts movement of coil to a position that could make ignition timing
illegal. If a coil support mount becomes stripped, it is permissible to heli-coil. However, only one leg
may be repaired, if both legs are heli-coiled, the block becomes illegal.
F. All nylon blades on the cooling fan
TIER III: Black Only
G. No metal removal or addition to flywheel is permitted.
H. A stock Honda spark plug cap, (wire end and resistor), must be used.
I. Any automotive type spark plug with ¾"reach maximum is allowed. Note Tapered seat spark plugs are illegal .
Race
DQ only.
J. Ignition coil air gap is no longer a tech item. Stated dimensions are recommended for safe operation will be:
0.008" minimum - 0.024" maximum.
K. No plug-indexing washers allowed.
L. If temperature sensor is used under spark plug, factory washer may be removed.
GEAR BOX AND RING GEAR
A. Gear box may not be altered in any way. May be rotated to desired position.
B. Ring gear may not be altered in any way with the exception of the keyed end of shaft that may be shortened, drilled
and tapped or machined for snap ring grove. No other machining, drilling, grinding etc. to ring gear. Keyway may
be cut deeper.
D. Ring gear may not be altered in any way including polishing or use of any compound or abrasive on gear shaft
where bearings ride.
E. Two gaskets maximum between gear box halves.
Flywheel weight will be: 1550 grams minimum
Flywheel diameter - magnet area: 6.285' minimum
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