MK Products Cobra MX Euro Compatible User manual

Product: Cobra MX
Manual: 091-0656
Serial: 11020001
Voltage Rating: 24 VDC
Revision: Sept 2013 Rev C
Gun models: 298-XXX A/C 1/4"
299-XXX W/C 1/4"
300-XXX A/C 3/8"
301-XXX W/C 3/8"
175 Ampere Air Cooled, 1/4" tip
200 Ampere Air Cooled, 3/8" tip
225 Ampere Water Cooled, 1/4" tip
250 Ampere Water Cooled, 3/8" tip
Push-Pull Welding Guns
Owner’s Manual
Euro Compatible™7 Pin
Shown with MAX Cup
Shown with Classic Cup

Table of Contents
Safety Considerations ........................................................................i-iii
Installation ............................................................................... Section A
Technical Specications.....................................................................................1
Support Equipment Required.............................................................................1
Coolant Requirements .......................................................................................1
Gun Lead Connections ......................................................................................1
Operation.................................................................................Section B
General ..............................................................................................................2
Controls and Settings.........................................................................................2
Trigger Adjustment .............................................................................................2
Drive Roll and Idler Rolls....................................................................................3
Accessories .............................................................................Section C
Optional Kits.......................................................................................................4
Conduits.............................................................................................................4
Snake Skins .......................................................................................................4
Contact Tips .......................................................................................................5
Gas Cups ...........................................................................................................6
Maintenance............................................................................Section D
Periodic Maintenance.........................................................................................6
Recommended Spare Parts List ........................................................................7
Troubleshooting.......................................................................Section E
Troubleshooting Guide.......................................................................................9
Testing The Gun.................................................................................................9
Appendices..............................................................................Section F
Diagrams / Parts List........................................................................................ 11
Mechanical.......................................................................................................12
Electrical...........................................................................................................30
Safety Warnings
Warranty

Declaration of Conformity for
European Community (CE) Products
Note
Manufacturer’s Name:
16882 Armstrong Ave.
Irvine, CA 92606
Declares that the product: Cobra®MX Euro Compatible™
conforms to the following Directives and Standards:
Directives
Low Voltage Directive: 2006/95/EC
Electromagnetic Compatibility (EMC) Directive: 2004/108/EC
Standards
Electromagnetic Compatibility, (EMC): EN 60974-10: 2007
Torches And Guns For Arc Welding, EN 60974-7: 2005

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page i
1-1 INTRODUCTION
This equipment is intended for ultimate
application by commercial/industrial
users and for operation by persons
trained and experienced in the use and
maintenance of welding equipment.
Operation should not be undertaken
without adequate training in the use of
such equipment. Training is available
from many public and private schools or
similar facilities.
Safe practices in the installation,
operation and maintenance of this
equipment requires proper training in the
art, a careful study of the information
provided with the equipment, and the
use of common sense. Rules for safe
use are generally provided by suppliers
of welding power sources, compressed
gas suppliers, and electrode suppliers.
Careful compliance with these rules will
promote safe use of this equipment.
The following Safety Rules cover some
of the more generally found situations.
READ THEM CAREFULLY. In case of
any doubt, obtain qualied help before
proceeding.
1-2 GENERAL PRECAUTIONS
ELECTRICARC WELDING PRODUCES
HIGH INTENSITY HEAT AND
ULTRAVIOLET RADIANT ENERGY
WHICH MAY CAUSE SERIOUS AND
PERMANENT EYE DAMAGE AND
WHICH MAY DAMAGE ANY EXPOSED
SKIN AREAS.
Wear helmet with safety goggles or
glasses with side shields underneath,
appropriate filter lenses or plates
(protected by clear cover glass). This
is a must for welding or cutting (and
chipping) to protect the eyes from radiant
energy and ying metal. Replace cover
glass when broken, pitted, or spattered.
Medical rst aid and eye treatment. First
aid facilities and a qualied rst aid
person should be available for each shift
unless medical facilities are close by for
immediate treatment of ash burns of
the eyes and skin burns.
Wear protective clothing - leather (or
asbestos) gauntlet gloves, hat, and high
safety-toe shoes. Button shirt collar and
pocket aps, and wear cufess trousers
to avoid entry of sparks and slag.
Avoid oily or greasy clothing. A spark
may ignite them.
Flammable hair preparations should
not be used by persons intending to
weld or cut.
Hot metal such as electrode stubs and
work pieces should never be handled
without gloves.
Ear plugs should be worn when working
on overhead or in a conned space. A
hard hat should be worn when others
work overhead.
WARNING: The use of this product may
result in exposure to chemicals known
to the State of California to cause cancer
and birth defects or other reproductive
harm.
Adequate ventilation. Severe discomfort,
illness or death can result from fumes,
vapors, heat, or oxygen enrichment or
depletion that welding (or cutting) may
produce. Prevent them with adequate
ventilation. NEVER ventilate with
oxygen.
Lead-, cadmium-, zinc-, mercury-,
beryllium-bearing and similar materials,
when welded or cut, may produce
harmful concentrations of toxic fumes.
Adequate local exhaust ventilation must
be used, or each person in the area,
as well as the operator, must wear an
air-supplied respirator. For beryllium,
both must be used.
Metals coated with or containing
materials that emit toxic fumes should
not be heated unless coating is removed
form the work surface, the area is well
ventilated, or the operator wears an
air-supplied respirator.
Work in a conned space only while it is
being ventilated and, if necessary, while
wearing an air-supplied respirator.
Gas leaks in a conned space should be
avoided. Leaked gas in large quantities
can change oxygen concentration
dangerously. Do not bring gas cylinders
into a conned space.
Leaving confined space, shut OFF
gas supply at source to prevent
possible accumulation of gases in the
space if downstream valves have been
accidentally opened or left open. Check
to be sure that the space is safe before
reentering it.
Vapors from chlorinated solvents can
be decomposed by the heat of the arc
(or ame) to form PHOSGENE, a highly
toxic gas, and other lung and eye irritating
products. The ultraviolet (radiant)
energy of the arc can also decompose
trichloroethylene and perchloroethylene
vapors to form phosgene. DO NOT
WELD or cut where solvent vapors can
be drawn into the welding or cutting
atmosphere or where the radiant energy
can penetrate to atmospheres containing
even minute amounts of trichloroethylene
or perchloroethylene.
Causes of fire and explosion are:
combustibles reached by the arc, ame,
flying sparks, hot slag, or heated
material, misuse of compressed gases
and cylinders, and short circuits.
BE AWARE THAT ying sparks or falling
slag can pass through cracks, along
pipes, through windows or doors, and
through wall or oor openings, out of
sight of the goggled operator. Sparks
can y many feet.
To prevent res and explosion:
Keep equipment clean and operable, free
of oil, grease, and (in electrical parts) of
metallic particles that can cause short
circuits.
If combustibles are in area, do NOT weld
or cut. Move the work if practicable, to
an area free of combustibles. Avoid paint
spray rooms, dip tanks, storage areas,
ventilators. If the work cannot be moved,
move combustibles at least 35 feet away,
out of reach of sparks and heat; or protect
against ignition with suitable and snug-
tting, re-resistant covers or shields.
Walls touching combustibles on opposite
sides should not be welded on (or cut).
Walls, ceilings, and floor near work
should be protected by heat-resistant
covers or shields.
Fire watcher must be standing by with
suitable re extinguishing equipment
during and for some time after welding
or cutting if:
1. Appreciable combustibles (including
building construction) are within 35
feet.
2. Appreciable combustibles are further
than 35 feet, but can be ignited by
sparks.
3. Openings (concealed or visible) in
oors or walls within 35 feet may expose
combustibles to sparks.
4. Combustibles adjacent to walls,
ceilings, roofs, or metal partitions can be
ignited by radiant or conducted heat.
Hot work permit should be obtained
before operation to ensure supervisor’s
approval that adequate precautions have
been taken.
After work is done, check that area is
free of sparks, glowing embers, and
ames.
An empty container that held
combustibles, or that can produce
ammable or toxic vapors when heated,
must never be welded on or cut, unless
container has first been cleaned in
accordance with industry standards.
This includes: a thorough steam or
caustic cleaning (or a solvent of water
washing, depending on the combustible’s
solubility), followed by purging and
inerting with nitrogen or carbon dioxide,
and using protective equipment.
Water-lling just below working level may
substitute for inerting.
A container with unknown contents
should be cleaned (see paragraph
above). Do NOT depend on sense of
smell or sight to determine if it is safe
to weld or cut.
Hollow castings or containers must be
vented before welding or cutting. They
can explode.
Explosive atmospheres. NEVER weld or
cut where the air may contain ammable
dust, gas, or liquid vapors (such as
gasoline).
The safe handling of compressed gas
equipment is detailed in numerous
industry publications. The following
general rules cover many of the most
ELECTRIC ARC WELDING EQUIPMENT

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page ii
common situations.
Regulator relief valve is designed
to protect only the regulator from
overpressure; it is not intended to protect
any downstream equipment. Provide
such protection with one or more relief
devices.
Never connect a regulator to a cylinder
containing gas other than that for which
the regulator was designed.
Remove faulty regulator from service
immediately for repair (rst close cylinder
valve). The following symptoms indicate
a faulty regulator:
Leaks - if gas leaks externally.
Excessive Creep - if delivery pressure
continues to rise with downstream valve
closed.
Faulty Gauge - if gauge pointer does
not move off stop pin when pressurized,
nor returns to stop pin after pressure
release.
Repair. Do NOT attempt repair. Send
faulty regulators for repair to
manufacturer’s designated repair center,
where special techniques and tools are
used by trained personnel.
Cylinders must be handled carefully to
prevent leaks and damage to their walls,
valves, or safety devices:
Avoid electrical circuit contact with
cylinders including third rails, electrical
wires, or welding circuits. They can
produced short circuit arcs that may lead
to a serious accident. (See 1-3C)
ICC or DOT marking must be on each
cylinder. It is an assurance of safety
when the cylinder is properly handled.
Identifying gas content. Use only
cylinders with name of gas marked on
them; do not rely on color to identify gas
content. Notify supplier if unmarked.
NEVER DEFACE or alter name, number,
or other markings on a cylinder. It is
illegal and hazardous.
Empties: Keep valves closed, replace
caps securely; mark MT; keep them
separate from FULLS, and return
promptly.
Prohibited use. Never use a cylinder or its
contents for other than its intended use,
NEVER as a support or roller.
Locate or secure cylinders so they
cannot be knocked over.
Passageways and work areas. Keep
cylinders clear of areas where they may
be stuck.
Transporting cylinders. With a crane,
use a secure support such as a platform
or cradle. Do NOT lift cylinders off the
ground by their valves or caps, or by
chains, slings, or magnets.
Do NOT expose cylinders to excessive
heat, sparks, slag, and ame, etc. that
may cause rupture. Do not allow contents
to exceed 55 degrees C (130 degrees
F.) Cool with water spray where such
exposure exists.
Protect cylinders, particularly valves from
bumps, falls, falling objects, and weather.
Replace caps securely when moving
cylinders.
Stuck valve. Do NOT use a hammer
or wrench to open a cylinder valve that
cannot be opened by hand. Notify your
supplier.
Mixing gases. NEVER try to mix any
gases in a cylinder.
NEVER rell any cylinder.
Cylinder ttings should never be modied
or exchanged.
Prohibited use. Never use hose other
than that designed for the specied gas.
A general hose identication rule is: red
for fuel gas, green for oxygen, and black
for inert gases.
Use ferrules or clamps designed for
the hose (not ordinary wire or other
substitute) as a binding to connect hoses
to ttings.
No copper tubing splices. Use only
standard brass ttings to splice hose.
Avoid long runs to prevent kinks and
abuse. Suspend hose off ground to keep
it from being run over, stepped on, or
otherwise damaged.
Coil excess hose to prevent kinks and
tangles.
Protect hose from damage by sharp
edges, and by sparks, slag, and open
ame.
Examine hose regularly for leaks,
wear, and loose connections. Immerse
pressured hose in water; bubbles indicate
leaks
Repair leaky or worn hose by cutting
area out and splicing. Do NOT use
tape.
Clean cylinder valve outlet of impurities
that may clog orices and damage seats
before connecting regulator. Except
for hydrogen, crack valve momentarily,
pointing outlet away from people and
sources of ignition. Wipe with a clean,
lintless cloth.
Match regulator to cylinder. Before
connecting, check that the regulator
label and cylinder marking agree, and
that the regulator inlet and cylinder outlet
match. NEVER Connect a regulator
designed for a particular gas or gases to
a cylinder containing any other gas.
Tighten connections. When assembling
threaded connections, clean and smooth
seats where necessary. Tighten. If
connection leaks, disassemble, clean,
and retighten, using properly fitting
wrench.
Adapters. Use a CGA adapter (available
from your supplier) between cylinder
and regulator, if one is required. Use
two wrenches to tighten adapter marked
RIGHT and LEFT HAND threads.
Regulator outlet (or hose) connections
may be identied by right hand threads
for oxygen and left hand threads (with
grooved hex on nut or shank) for fuel gas.
Drain regulator of residual gas through
suitable vent before opening cylinder
(or manifold valve) by turning adjusting
screw in (clockwise). Draining prevents
excessive compression heat at high
pressure seat by allowing seat to open
on pressurization. Leave adjusting
screw engaged slightly on single-stage
regulators.
Stand to side of regulator while opening
cylinder valve.
Open cylinder valve slowly so that
regulator pressure increases slowly.
When gauge is pressurized (gauge
reaches regulator maximum) leave
cylinder valve in following position: for
oxygen and inert gases, open fully to
seal stem against possible leak; for fuel
gas, open to less than one turn to permit
quick emergency shut-off.
Use pressure charts (available from
your supplier) for safe and efficient
recommended pressure settings on
regulators.
Check for leaks on rst pressurization
and regularly thereafter. Brush with
soap solution. Bubbles indicate leaks.
Clean off soapy water after test; dried
soap is combustible.
Follow all Safety Rules.
Remove leaky or defective equipment
from service immediately for repair. Read
and follow user manual instructions.
Close gas supply at source and drain
gas.
Rope staging-support should not be
used for welding or cutting operation;
rope may burn.
1-3 ARC WELDING
Comply with precautions in 1-1, 1-2, and
this section. Arc Welding, properly done,
is a safe process, but a careless operator
invites trouble. The equipment carries
high currents at signicant voltages.
The arc is very bright and hot. Sparks
y, fumes rise, ultraviolet and infrared
energy radiates, weldments are hot,
and compressed gases may be used.
The wise operator avoids unnecessary
risks and protects himself and others
from accidents.
Comply with precautions in 1-2.
The welding arc is intense and visibly
bright. Its radiation can damage eyes,
penetrate lightweight clothing, reect
from light-colored surfaces, and burn
the skin and eyes. Skin burns resemble
acute sunburn; those from gas-shielded
arcs are more severe and painful.

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page iii
DON’T GET BURNED; COMPLY WITH
PRECAUTIONS.
Wear long-sleeve clothing in addition to
gloves, hat, and shoes. As necessary,
use additional protective clothing such
as leather jacket or sleeves, ameproof
apron, and re-resistant leggings. Avoid
outer garments of untreated cotton.
Bare skin protection. Wear dark,
substantial clothing. Button collar to
protect chest and neck, and button
pockets to prevent entry of sparks.
Protect eyes from exposure to arc. Eyes
may be damaged by radiant energy
when exposed to the electric arc, even
when not looking in the direction of the
arc. Never look at an electric arc without
protection.
Welding helmet or shield containing a
lter plate shade no. 12 or denser must
be used when welding. Place over face
before striking arc.
Protect lter plate with a clear cover
plate.
Cracked or broken helmet or shield
should NOT be worn; radiation can be
passed through to cause burns.
Cracked, broken, or loose lter plates
must be replaced IMMEDIATELY.
Replace clear cover plate when broken,
pitted, or spattered.
Flash goggles with side shields MUST
be worn under the helmet to give some
protection to the eyes should the helmet
not be lowered over the face before an arc
is struck. Looking at an arc momentarily
with unprotected eyes (particularly a high
intensity gas-shielded arc) can cause a
retinal burn that may leave a permanent
dark area in the eld of vision.
Enclose the welding area. For production
welding, a separate room or enclosed
bay is best. In open areas, surround
the operation with low-reflective,
noncombustible screens or panels. Allow
for free air circulation, particularly at
oor level.
Viewing the weld. Provide face shields
for all persons who will be looking directly
at the weld.
Others working in area. See that all
persons are wearing ash goggles.
Before starting to weld, make sure that
screen aps or bay doors are closed.
Comply with precautions in 1-2B.
Generator engine exhaust must be
vented to the outside air. Carbon
monoxide can kill.
Comply with precautions in 1-2C.
Equipment’s rated capacity. Do not
overload arc welding equipment. It may
overheat cables and cause a re.
Loose cable connections may overheat
or ash and cause are.
Never strike an arc on a cylinder or other
pressure vessel. It creates a brittle
area that can cause a violent rupture or
lead to such a rupture later under rough
handling.
Comply with precautions in 1-2D.
Exposed electrically hot conductors or
other bare metal in the welding circuit,
or in ungrounded, electrically-HOT
equipment can fatally shock a person
whose body becomes a conductor. DO
NOT STAND, SIT, LIE, LEAN ON, OR
TOUCH a wet surface when welding
without suitable protection.
To protect against shock:
Keep body and clothing dry. Never
work in damp area without adequate
insulation against electrical shock. Stay
on a dry duckboard, or rubber mat when
dampness or sweat cannot be avoided.
Sweat, sea water, or moisture between
body and an electrically HOT part -
or grounded metal - reduces the body
surface electrical resistance, enabling
dangerous and possibly lethal currents
to ow through the body.
When installing, connect the frames of
each unit such as welding power source,
control, work table, and water circulator
to the building ground. Conductors must
be adequate to carry ground currents
safely. Equipment made electrically HOT
by stray currents may shock, possibly
fatally. Do NOT GROUND to electrical
conduit, or to a pipe carrying ANY gas or
a ammable liquid such as oil or fuel.
Three-phase connection. Check phase
requirement of equipment before
installing. If only three-phase power
is available, connect single-phase
equipment to only two wires of the
three-phase line. Do NOT connect the
equipment ground lead to the third (live)
wire, or the equipment will become
electrically HOT - a dangerous condition
that can shock, possibly fatally.
Before welding, check ground for
continuity. Be sure conductors are
touching bare metal of equipment frames
at connections.
If a line cord with a ground lead is provided
with the equipment for connection to
a switch box, connect the ground lead
to the grounded switch box. If a three-
prong plug is added for connection to a
grounded mating receptacle, the ground
lead must be connected to the ground
prong only. If the line cord comes with a
three-prong plug, connect to a grounded
mating receptacle. Never remove the
ground prong from a plug, or use a plug
with a broken ground prong.
Fully insulated lock-type connectors
should be used to join welding cable
lengths.
Frequently inspect cables for wear,
cracks, and damage. IMMEDIATELY
REPLACE those with excessively worn
or damaged insulation to avoid possibly
lethal shock from bared cable. Cables
with damaged areas may be taped to give
resistance equivalent to original cable.
Keep cable dry, free of oil and grease, and
protected from hot metal and sparks.
Parts
Terminals and other exposed parts of
electrical units should have insulating
covers secured before operation.
Electrode wire becomes electrically HOT
when the power switch of gas metal-arc
welding equipment is ON and welding
gun trigger is pressed. Keep hands
and body clear of wire and other HOT
parts.
Safety devices such as interlocks
and circuit breakers should not be
disconnected or shunted out.
Before installation, inspection, or service
of equipment, shut OFF all power, and
remove line fuses (or lock or red-tag
switches) to prevent accidental turning
ON of power. Disconnect all cables from
welding power source, and pull all 115
volts line-cord plugs.
Do not open power circuit or change
polarity while welding. If, in an
emergency, it must be disconnected,
guard against shock burns or ash from
switch arcing.
Leaving equipment unattended. Always
shut OFF, and disconnect all power to
equipment.
Power disconnect switch must be
available near the welding power
source.

Thank
You For selectingaquality product. We want you to take
pride in operating this product...as much pride as we
have in bringing the product to you!
When this equipment is shipped, title passes to the purchaser upon receipt by the
carrier.Consequently, claims for material damaged in shipment must be made by the
purchaser against the transportation company at the time the shipment is received.
Please record your equipment identification information below for future reference. This
information can be found on your machine nameplate.
Model Name&Number _____________________
Code&Serial Number _____________________
Date of Purchase _____________________
Whenever you request replacementsparts for,or information on this equipment always
supply the information you have recorded above.
Please Examine Carton and Equipment For Damage Immediately
Read this Owner’s Manual completely before attempting to use this equipment. Save this manual
and keep it handy for quick reference. Pay particular attention to the safety instructions we
have provided for your protection.

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 1
Section A Installation
.030" - .045" (0.8mm - 1.2mm) solid hard wire, and cored wire
.030" - 1/16" (0.8mm - 1.6mm) aluminum
Wire Speed
800 IPM (20.3 mpm) max
All ratings are using Argon gas
175 Amps/25 Volts Air Cooled, 1/4" Tip (Model 298)
200 Amps/25 Volts Air Cooled, 3/8" Tip (Model 300)
225 Amps/25 Volts Water Cooled, 1/4" Tip (Model 299)
250 Amps/25 Volts Water Cooled, 3/8" Tip (Model 301)
• C.V. or C.C. power source of sufcient capacity for your needs.
•Regulated gas supply and hoses.
•Properly sized power leads from power source to wire feeder and
ground.
•Water source and hose capable of providing a minimum of
when using water cooled guns.
WARNING: Use only Cobra Coolant - failure to use coolant will void
warranty.
Use Cobra Coolant (Aluminum Protection),which does not contain reactive
sulphur or chlorine and does not react with copper, brass or aluminum. The
Cobra Coolant is available in quantities of 1 gallon (P/N 931-0060), 5 gallon
(P/N 931-0060-5GAL), or a case of 4 gallons each (P/N 931-0060-4).
The coolant ow rate should be a minimum of 10 GPH (1 qt/min) between
35 and 45psi. Contact the re-circulator manufacturer for specications on
pressure.
Gun Lead Connections
Power Cable - Air Cooled
A #2 power cable is used on the Cobra MX Euro Compatible 7 Pin gun. The
gun and Euro Power Manifold ends of the cable are stripped to the copper
strands and wrapped with a copper strip. A setscrew holds the cable securely
in the gun body and in the Euro Power Manifold with torque requirements of
55-60 in-lb.
Power Cable - Water Cooled
The Cobra MX Euro Compatible 7 Pin water cooled gun utilizes a power/
water cable with a #6 AWG cable inside a 5/16” diameter hose.
The power cable ends are threaded ttings which screw into the gun body
and the Euro Power Manifold. These connections utilize a conductive sealant
and are tightened with torque requirements of 100 + 5 IN-LB.
Conduit
The Cobra MX Euro Compatible 7 Pin gun comes standard with a poly-
lined conduit, for feeding aluminum wire. The longer tting with a shallow
groove is used on the gun end. A set screw located on top of the gun handle
secures the conduit in place. The cabinet end of the conduit is secured into
the Euro Power Manifold with a set screw.
The BLACK gas hose is pushed over a barbed tting on the end of the gun
body and secured by twisting the hose retainer to the end of the hose (shown
next page). The opposite end of the BLACK hose is pushed over a barbed
tting in the Euro Power Manifold. The hose retainer is re-usable and can be
removed and re-installed as needed.

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 2
Coolant Connections
If so equipped, the ends of the coolant hose push over a barbed tting on
the end of the gun body and are secured by twisting the hose retainer to the
end of the hose. The hose retainer is re-usable and can be removed and
re-installed as needed.
The BLUE coolant supply hose pushes over a barbed tting on the end of
the gun body and is secured by twisting the hose retainer to the end of the
hose. The hose retainer is re-usable and can be removed and re-installed as
needed.The opposite end of the BLUE hose pushes into a threaded coolant
tting.
The RED coolant return hose pushes over the barbed tting in the Power
Manifold. The opposite end of the RED hose pushes into a threaded return
hose of the coolant recirculator.
Both the BLUE and RED threaded ttings on the end of the BLUE and RED
hoses, are standard left-hand thread. MK Products compatible guns have
interchangeable ttings, so you can match as needed for your cooler. Both
types of ttings require a hose retainer.
Control Cable
A multi-conductor control cable is used on the Cobra MX Euro Compatible 7
Pin. The gun end of the cable is secured with a cable clamp and the wires
are connected to the potentiometer, the micro switch, the motor and the gun
body mechanically. Slack is left in the electric cable as it exits the back of the
gun to prevent cable and/or wire breakage. The cabinet end has a seven pin
"W" clocked amphenol connector.
General
The Cobra MX Euro Compatible 7 Pin gun maintains a constant, steady,
uniform wire feed speed, regardless of curved or looped wire conduit. The
constant push exerted by the slave motor in the cabinet, combined with the
pull of the gun motor, causes the wire to literally oat friction-free through
the wire conduit. The 24VDC gun motor is controlled by a three and three-
quarter (3 3/4) turn potentiometer in the gun handle.
Controls and Settings
Potentiometer
The laterally-positioned potentiometer is located in
the lower end of the handle, providing up to 800 ipm
with 3 3/4 turns.
Micro Switch
The micro switch assembly consists of the micro
switch, and leads.
The amount of trigger lever travel can be shortened
for a quicker or more responsive action.
A more sensitive trigger lever is produced by
reducing the gap between the trigger lever and the
micro switch lever. By turning-in the trigger sensitivity
adjustment screw, it closed the gap between the
Trigger Sensitivity Adjustment
Screw Location
Screw adjusted out of trigger,
pre-setting the micro-switch
lever for shorter motion
sensitivity.
431-1898
5/16” Hose Retainer
431-1910
Quick Connect Fitting
431-1893*
Nipple
753-3379*
Left-Hand Threaded Fitting
*Must be ordered together

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 3
trigger lever and the micro switch lever.
This will enable the operator to increase the sensitivity of the trigger lever.
With the wire feeder turned on (with or without welding wire loaded), turn the
screw in until the micro-switch is activated. Once activated, the gun and wire
feeder motors will begin feeding wire. Retract the screw accordingly until the
system is deactivated and adjusted to the operators' liking.
Drive Roll and Idler Rolls
General
The Cobra MX Euro Compatible 7 Pin gun comes standard with a knurled
drive roll and a grooved idler roll, which will handle aluminum wire with
diameters of .030 to 1/16 inch and steel from .030 to .045 inches. Optional
insulated V-groove drive rolls are also available for aluminum wire if desired
(see optional kits).
Drive roll tension is accomplished with a unique spring-loaded pressure
screw. The Cobra MX Euro Compatible 7 Pin comes from the factory
with the pressure adjustment screw preset. NO ADJUSTMENT IS
.
Drive Roll Installation/Removal
Note: Neither of the handles needs to be removed to access the drive or
idler rolls.
Pull the cam lever away from the idler roll. This
will relieve the pressure against the drive roll (as
shown in Figure 1).
Align the drive roll removal tool (P/N 931-0100)
over the ats of the drive roll (as shown in Figure
2). Hold the gun with one hand or on a table
top, with the other hand give the removal
tool a quick snap-turn in the CLOCKWISE
DIRECTION.
Once the drive roll is loose, continue to spin
drive roll in the clockwise direction to remove
the drive roll from the gun.
Install a new drive roll on the left-hand
threaded shaft. The drive roll will self-tighten
when it is feeding wire.
Idler Roll Installation and Removal
(Reference Figure 3)
Using a slot type screwdriver, loosen idler screw, taking care not to lose
lock washer under idler roll.
Insert new idler roll and lock washer onto screw, insuring that idler groove
is toward top and lock washer is beneath.
Tighten.
NOTE: Lock washer must be under idler roll or it will not turn freely.
Cam Lever

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 4
Section C Accessories
Optional Kits
Insulated Drive Roll Kits are used to prevent preheating of the aluminum wire
which may soften it and clog the liner. This picking up of current at the drive
rolls rather than at the contact tip is usually not a problem unless using too
large of a contact tip or excessively oxidized aluminum wire.
Insulated Grooved Drive Roll Kit 005-0715
For (0.8mm) dia. aluminum wire. Includes insulated groove drive roll
and insulated idler roll assy.
Insulated Grooved Drive Roll Kit 005-0716
For (0.9mm) dia. aluminum wire. Includes insulated groove drive roll
and insulated idler roll assy.
Insulated Grooved Drive Roll Kit 005-0717
For (1.0mm) dia. aluminum wire. Includes insulated groove drive roll
and insulated idler roll assy.
For 3/64" (1.2mm) dia. aluminum wire. Includes insulated groove drive roll
and insulated idler roll assy.
For (1.6mm) dia. aluminum wire. Includes insulated groove drive roll
and insulated idler roll assy.
Includes left and right handles, screws and drive roll door.
Trigger kit includes a sensitivity adjustment screw replacement for all Cobra
MX Euro Compatible 7 Pin guns.
Replacement micro switch assembly for all Cobra MX Euro Compatible 7 Pin
guns.
Replacement potentiometer assembly for all Cobra MX Euro Compatible
7 Pin guns.
Conduits
615-0621-15 .................................................................................... 15 ft./4.5m
615-0621-25 .................................................................................... 25 ft./7.6m
615-0621-35 .................................................................................. 35 ft./10.7m
615-0621-50 .................................................................................. 50 ft./15.2m
Optional nickle tube liner................................................................003-2281
Snake Skin protective covers are now standard on all guns. You may order
spare replacement covers to protect the lead assy of the gun when the
factory one becomes damaged or worn. It can easily be replaced in the eld
by means of Velcro©.
Snake Skin Cover 13ft (for 15ft leads) ........................................ 931-0110
Snake Skin Cover 23ft (for 25ft leads) ........................................ 931-0122
Snake Skin Cover 33ft (for 35ft leads) ........................................ 931-0132
Snake Skin Cover 48ft (for 50ft leads) ........................................ 931-0123

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 5
Gas Valve Removal Tool
Gas valve removal is often required to replace the standard valve stem with
a modied valve stem (P/N 431-1080) when placing an older model gun on
a newer model wire feeder. This is performed by using P/N 931-0105 Gas
Valve Removal Tool. This multifunctional tool has been slotted on one side
to encompass and conform to the gas valve stem and seat into the slotted
gas valve body as seen in Figures 1 and 2. Removal of the gas valve can be
accomplished by turning the gas valve tool counter clockwise. Reinstall by
turning clockwise. The tool doubles as a bottle opener.
Gas Valve Removal Tool Figure 2Figure 1
Contact Tips
Tip ID Arc Tip Length
.030” (0.8mm) .041” (1.0mm) Spray 1.57” (39.9mm) 621-0390-25
Short 1.82” (46.2mm) 621-0396-25
.035” (0.9mm) .044” (1.1mm) Spray 1.57” (39.9mm) 621-0391-25
621-0391-250†
621-0391-500††
.035" (0.9mm) .044" (1.1mm) Short 1.82” (46.2mm) 621-0397-25
.045" (1.1mm) .053" (1.35mm) Short 1.82” (46.2mm) 621-0398-25
3/64” (1.2mm) .053” (1.35mm) Spray 1.57” (39.9mm) 621-0392-25
621-0392-250†
621-0392-500††
3/64” (1.2mm) .060” (1.5mm) Spray 1.57” (39.9mm) 621-0393-25**
621-0393-250†
621-0393-500††
1/16” (1.6mm) .074” (1.9mm) Spray 1.57” (39.9mm) 621-0394-25
.085” (2.16mm) Spray 621-0395-25
*Use of tip removal tool is recommended
†
Also
sold in quantities of 250
**This size tip furnished with gun
† †
Also
sold in quantities of 500
1/4" Diameter Contact Tip*
Tip ID Arc Tip Length
.023” (0.6 mm) .031” (0.8 mm) Spray 1.50” (38.1 mm) 621-0057-25
.023” (0.6 mm) .031” (0.8 mm) Short 1.75” (44.5 mm) 621-0328-25
.030” (0.8 mm) .036” (0.9 mm) Spray 1.50” (38.1 mm) 621-0325-25
.030” (0.8 mm) .037” (0.9 mm) Short 1.75” (44.5 mm) 621-0326-25
.035"/.030”
(0.9 mm /0.8 mm)
.041” (1.0 mm) Spray 1.50” (38.1 mm) 621-0076-25
.035” (0.9 mm) .044” (1.1 mm) Spray 1.50” (38.1 mm) 621-0001-25
621-0001-250†
621-0001-500††
.035” (0.9 mm) .041” (1.0 mm) Short 1.75” (44.5 mm) 621-0077-25
.035” (0.9 mm) .044” (1.1 mm) Short 1.75” (44.5 mm) 621-0002-25
3/64” (1.2 mm) .053” (1.35 mm) Spray 1.50” (38.1 mm) 621-0327-25
3/64” (1.2 mm) .060” (1.5 mm) Spray 1.50” (38.1 mm) 621-0003-25**
621-0003-250†
621-0003-500††
1/16” (1.6 mm) .074” (1.9 mm) Spray 1.50” (38.1 mm) 621-0075-25
1/16” (1.6 mm) .085”(2.1 mm) Spray 1.50” (38.1 mm) 621-0153-25
**This size tip furnished with gun
* All tips sold in quantities of 25
† Also sold in quantities of 250
† † Also sold in quantities of 500

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 6
Section D Maintenance
Periodic Maintenance
Your Cobramatic system is designed to provide years of reliable service.
Maintenance of the gun will normally consist of a general cleaning of the wire
guide system, including barrels, drive rolls, and conduits at regular intervals.
Remove spatter build-up from inside of nozzles with a hardwood stick.
The only parts on the Cobramatic system that are subject to normal wear are
the conduit, contact tips, gas cups, front body liners, wire guides, drive and
idler rolls. A supply of these parts should be maintained on hand.
The number of units in operation and the importance of minimal down time
will determine to what extent spare parts should be stocked on hand. See
the recommended spare parts list for the most commonly replaced parts.
If repairs do become necessary, qualied shop maintenance personnel can
easily replace any part.
Part Number Description
931-0137 Teon liner package, 5 pieces
615-0341 Steel wire only, .030 - 1/16" (0.8 - 0.9mm)
621-0423 Tip Extender, MAX Cup (stackable)
621-0017 Tip Extender, Classic Cup (stackable)
615-0248 Spiral steel liner for tip extender
MAX Cups
Classic Cups
#6, 3/8" (9.5mm) 621-0420 #5, 1/4" (6.4mm) 621-0079
#8, 1/2" (12.7mm) 621-0421* #6, 3/8" (9.5mm) 001-0137-4†
#10, 5/8" (15.9mm) 621-0422 #8, 1/2" (12.7mm) 001-0138-4*†
#10, 5/8" (15.8mm) 001-0139-4†
*standard - furnished with gun
†sold in packs of 4 each
Maintenance Tools
Tool Part Number
Contact Tip Removal Tool 931-0044
Drive Roll Removal Tool 931-0100
Spring Loaded Contact Tip - 3/8” Diameter
Tip ID Arc Tip Length Part Number
.030” (0.8 mm) .041” (1.0 mm) Spray 1.57” (39.9 mm) EA 621-0331
.035” (0.9 mm) .044” (1.1 mm) Spray 1.57” (39.9 mm) EA 621-0332
3/64” (1.2 mm) .060” (1.5 mm) Spray 1.57” (39.9 mm) EA 621-0334
1/16” (1.6 mm) .074” (1.9 mm) Spray 1.57” (39.9 mm) EA 621-0335
Tip Extender

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 7
Recommended Spare Parts List
Description
1 615-0620-15 Conduit - 15 ft
1 615-0620-25 Conduit - 25 ft
1 615-0620-35 Conduit - 35 ft
1 615-0620-50 Conduit - 50 ft
2 005-0726 Trigger Assy Kit
2 003-2190 Potentiometer Assy Kit
1 005-0725 Handle Kit
2 003-2274 Micro-Switch Assy Kit
10 511-0101 Drive Roll
5 511-0001 Idler Roll
KNURLED DRIVE ROLL
511-0101
DRIVE ROLL REMOVAL TOOL
931-0100
IDLER ROLL
511-0001
MICRO SWITCH ASSY
003-2274
IDLER ROLL
511-0113

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 8
Section E Troubleshooting
Trouble Cause
No wire feed at
gun, feeder not
operating, i.e. no
slave motor or
brake solenoid.
Input power fuse in
feeder/control box blown Replace fuse.
Micro-switch defective/
not being activated
Replace switch. Check
switch for operation.
Broken electrical cable Check micro-switch wires
for continuity.
No wire feed
at gun, feeder
operating properly.
Motor control fuse in
feeder/control box blown
Check motor leads for
shorts; then replace fuse.
Bad potentiometer Check potentiometer with
meter.
Broken electrical cable.
Check motor and
potentiometer wires for
continuity.
Bad speed control/PCB.
See specic cabinet/
control box owner's
manual for speed control
operation.
Wire feeds, but
welding wire is not
energized.
Loose or no cable
connections.
Check all power
connections.
Contactor control cable
loose or in wrong position
Check power supply
owner's manual for
location and type of
contactor signal required,
i.e. closing or 115VAC.
Welding power source Check power source.
Wire feeds
erratically.
Dirty or worn conduit Blow out or replace
conduit.
Wrong size contact tip See contact tip table.
Idler roll stuck
Check for lock washer
under idler roll, or replace
if damaged.
Wire feeds one
speed only.
Bad potentiometer Check with meter.
Broken electrical cable
Check potentiometer
wires for continuity or
short.
Bad speed control
See specic cabinet/
control owner's manual for
speed control operation.
Wire walks out of
drive rolls.
Idler roll upside-down Place groove in idler roll
toward top.
Rear wire guide missing Replace wire guide.

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 9
Troubleshooting Guide
Regardless of which gun or feeder used, all MK Products’ push-pull guns
operate on the same principle. The slave motor in the feeder runs at a
fast,constant speed, but has very low torque. It is always trying to feed
more wire than the gun motor wants, and when the motor gets all it wants, it
slows the slave motor, preventing a bird’s nest. Because of the low torque
produced by the slave motor, a brake system is used to prevent wire overrun
rather than tension. The drag adjustment in the feeder is used simply to
keep the wire slightly taut, so it will not pull off the spool while feeding wire.
The high torque 24VDC gun motor is controlled by a solid state speed
control located in the feeder, and a pot located in the gun. The gun motor,
potentiometer, and micro switch are connected to the cabinet/control box via
a control cable and Amphenol connector. If this cable becomes damaged, a
variety of symptoms can occur, depending on which wire(s) break. To test,
check each wire for continuity and shorts.
Remember, the micro switch in the gun activates both the slave motor and
gun motor circuits in the cabinet. Therefore, if the slave motor and brake
solenoid operate, but the gun does not, look more toward the gun motor’s 24
V circuits, speed control, control cable, or the gun motor. If nothing operates,
look more toward the slave motor’s input, micro switch leads, or micro switch.
Testing The Gun
Reference the "W" clocked gun wiring diagram on
the Cobra MX Euro Compatible 7 Pin electrical diagram
for information about pin-outs and locations.
Remove the gun connector from the cabinet.
Using the gun Amphenol connector, check the resistance across pins “A”
and (motor leads).
If an open circuit (more than K ohms) or short exist (less than 2 ohms)
exists, check the motor leads and motor independently.
Using the gun amphenol connector, check the resistance across pin “D”
(wiper) and pin “C”. The resistance should vary from 0 - 5K ohms as the
potentiometer is turned.
Check the resistance across pin “D” (wiper) and pin “G”. The resistance
should vary from 5K - 0 ohms as the potentiometer is turned.
Testing the Micro Switch
Using the gun amphenol connector, check for continuity across pins “E” and
when the trigger is pressed.

THIS PAGE INTENTIONALLY BLANK

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 11
Appendices
Diagrams / Parts List
Exploded View .......................................................................... 12
Bill of Material ........................................................................... 13
Front Body Assembly................................................................ 14
Rear Body Assembly, Air Cooled .............................................. 15
Rear Body Assembly, Water Cooled......................................... 16
Classic Cup Barrel Assembly, Air Cooled ................................. 17
Classic Cup Barrel Assembly, Water Cooled............................ 18
MAX Barrel Assembly, Air Cooled............................................. 19
MAX Cup Barrel Assembly, Water Cooled................................ 20
Spiral Wrap Installation............................................................. 21
Lead Assembly, Air Cooled ....................................................... 24
Lead Assembly, Water Cooled.................................................. 26
Power Manifold Assembly, Air Cooled ...................................... 28
Power Manifold Assembly, Water Cooled ................................. 29
Electrical ................................................................................... 30

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 12
Cobra MX Euro Compatible

Cobra® MX Euro Compatible™ 7 Pin Owner's Manual - Page 13
Cobra MX
Description Description
1 1 002-0629 Assy Cam Idler Arm 12 4 333-0260 Wshr, Spr, LK #6 SST
2 1 003-2141 Front Body 13 5 333-0261 Wshr, Spr, LK #8 SST
3 1 003-2190 Assy Pot 14 7 338-0014 Scr Shc 4-40 x 1/2 SST
4 1 003-2274 Assy Switch 15 4 338-0022 Scr Shc 6-32 x 3/8 SST
5 1 005-0726 Trigger Kit 16 5 338-0034 Scr Shc 8-32 x 1/2 SST
61 003-2397 Assy Rear Body, AC 17 2 405-0706 Label Serial Plate
1 003-2398 Assy Rear Body, WC 18 1 405-1312 Label Warning
71 211-0085 Standard Motor 19 1 421-0452 Pin Dowel 3/32 x 0.80 LG
1 211-0080 High Speed Motor (optional) 20 1 431-1892 Scr Shoulder 1/8 Door MX
8 1 301-0093 Boot Torch 21 1 435-1585 Strap Motor
9 2 319-0254 Scr FH Phil 82 4-40 x 3/8 SST 22 1 437-0253 Door Molded
10 1 319-0258 Scr FH Phil 4-40 x 5/8 SST 23 1 005-0725 Handle Kit: Includes line items 14, 20,
and 22
11 3 320-0101 Scr Button 4-40 x 3/16 SST 24 1
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