General Rules - Honda GX 120 Tech Manual

HONDA CLAIM RULE - For GX120 QMA Type Engines
1. All engine claims must follow procedure listed in QMA rulebook. Please see Article 6, Section 1
HONDA SUSPENSIONS
1. All suspensions must follow procedure listed in QMA rulebook. Please see Article 6, Section 2

GENERAL RULES

1. Only stock Honda GX120K1 engine and gearbox will be used in this class.
parts will be stock Honda specifically made for the Honda GX12OK1 HX2.
GCAAT UY-2 = GCBMT
Honda replacement block 12000-Z0S-416 IS ALLOWED
2.
All stock Honda parts must be used and properly installed with the following exceptions:
The following (listed below) gaskets that are coming from Honda are tan & green will be legal to use
Intake Gasket, Carb Gasket, Side Cover Gasket
A. Governor System may be partially or fully removed with the exception of the steel drive gear on the
crankshaft. This gear must remain intact. If shaft is removed hole must be plugged. Hole can be tapped
for thread or epoxy. No welding.
B. Factory air cleaner must be removed. Any air filter may be attached to the outside of air filter adapter.
Outer wear style or equivalent can be used over carburetor only with no adapter. The approved air filter
adapter may be run with or without an air filter. Any air filter may be used with adapter as long as there
are no devices inside the air filter or adapter. (I.E. Springs not allowed) Hose from valve cover must go
into a catch can. (We are using "outerwear" to define a style not brand name).
1. The use of air filters during qualifying at asphalt and dirt events is illegal. The Senior Tech. Official
reserves the right to allow filters at any event that it's deemed necessary.
C. Stock Honda fuel tank must be removed.
D. Recoil starter must be removed. Pull cup may be cut down for washer. Must use original cup.
E. Exhaust: Stock Honda muffler will be removed. Mounting flange may be cut off of muffler and used as
adapter flange. Any transition from the "D" shape of the exhaust port to round must take place with in the
thickness (0.250" max.) of the flange. This applies to all exhaust systems. No steps or tapers allowed, pipe
must be 1piece continuous pipe from flange or slip nipple to muffler coupler. No sections of pipe welded
together (BUTT WELDS). grind marks are allowed past 0.250" flange area. No suspension for exhaust
flange or pipe infraction just disqualification. If an after market flange is used, maximum allowable flange
thickness will be 0.250 inches. If slip on type flange assembly is used, pipe stub will be a maximum 0.880
inches outside diameter tubing with a maximum overall length of 1.500" inches. Pipe stub must be
inserted into exhaust pipe at least 0.750 inches and will have minimal exhaust leakage. Muffler to be used
will be 4 to 8 hp Briggs & Stratton, part number 294599 or equal equivalent. Muffler will be internally
unaltered except that the round cup shaped baffle may be welded to the perforated baffle without moving
its original location. Threads will not be removed from muffler. Exhaust pipe will be a maximum of
1.000" inches outside diameter with a length of 20.0" to 26.0" including a threaded pipe coupler to
welded to the end of the pipe in order to screw muffler in place so that muffler may be removed for
inspection. Pipe coupler will be a standard, unaltered, ¾" NP, threaded coupler. Length will be 1.000"
inches minimum to 2.250" inches maximum. There will be no steps or tapers in exhaust pipe or flange
assembly. Exhaust pipe length will be measured by using a small diameter hose inserted though pipe to
measure over all length. Flange and coupler will be included in the overall length when measuring pipe.
No coating of any type may be applied to the interior of any part of the exhaust system. The intent of this
rule is to have all of the exhaust pass through the muffler. All measurements are to be taken with the
component pieces in the same position as they were installed and on the car.
F. Choke butterfly and shaft must be removed. Hole may be filled only with silicone. Or old shaft cut down.
G. Oil level switch may be disconnected but switch assembly must remain intact in crankcase.
H. Gearbox may be rotated to any desired position.
I. Main jet in carburetor may be a maximum of #70 Max Some jets will be silver in color, they
are legal.
J. Off-On ignition switch may be removed, and hole covered. (Any material; no welding)
K. All pin measuring gauges are plus tolerance.
L. Exhaust oxygen sensor or temp. Sensor attached to any part of Honda exhaust system is illegal.
1. All QMA ¼ midget mufflers must be Briggs & Stratton Part # 294599 or equivalent. No
drilling holes in the baffles. Inside seam of baffle must be straight edged. (NOTE: Some
seams may not be parallel in baffle) You cannot cut off the threaded flange if it is to be used
in Honda. It is OK to weld a washer or nut on the flange for a place to apply safety wire.
No aftermarket blocks allowed
U.S. = GCAHK. Canada =
All
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