Ardisam Viper Installation and operation manual

ENGINES
OM6036507
Rev. 9/26/08
© 2008 Ardisam, Inc.
All Rights Reserved. Printed in USA.
OPERATING & MAINTENANCE
INSTRUCTIONS
6.5 hp 4-STROKE ENGINE

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
INTRODUCTION
Thank You . . .
for purchasing a Viper engine from Ardisam, Inc. We have worked to
ensure that our product meets high standards for usability and durability.
With proper care, your engine will provide many years of excellent service.
Please take the time to read this manual carefully to learn how to correctly
operate and maintain your Viper engine. Due to continuous efforts to per-
fect our products, certain procedures and specifications are subjected to
change without notice. Congratulations on your investment in quality.
CONTENTS
Introduction ................................................................................................ 2
General Safety Precautions .................................................................... 3-4
Engine Components................................................................................... 5
Pre-Operation Procedures ......................................................................6-7
Engine Operation .................................................................................... 8-9
Maintenance............................................................................................. 10
Engine Maintenance ...........................................................................11-13
Battery (Electric Models Only) ............................................................13-14
Transporting and Storage......................................................................... 14
Service and Troubleshooting...............................................................15-16
Parts Explosion/Parts List ...................................................................17-18
Registration/Warranty............................................................................... 19
FEDERAL EMISSION INFORMATION
Ardisam, Inc. warrants to the retail purchaser, that this small, off-
road engine was designed, built and equipped to conform at the
time of initial sale to all applicable regulations of the U.S. Environ-
mental Protection Agency (EPA).

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
GENERAL SAFETY PRECAUTIONS
Please read this section carefully. Operate the engine according to the
safety instructions and recommendations outlined here and inserted
throughout the text. Anyone who uses this engine must read the instruc-
tions and be familiar with the controls.
Owner’s Responsibility:
It is the owner’s responsibility to accurately assemble the engine for safe
and effective use.
• Read and follow all safety instructions.
• Carefully follow all assembly instructions.
• Maintain the engine according to directions and schedule included in
this operator’s manual.
• Ensure that anyone who uses this engine is familiar with all controls
and safety precautions.
SIGNAL WORDS
A signal word alerts you to potential hazards that could harm
you or others. Each signal word is preceded by the safety alert
symbol followed by the word DANGER, WARNING, CAUTION or
IMPORTANT.
Each signal word will make you aware of what the hazard is, what can
happen, and what you can do to prevent or decrease injury occur-
rence.
WARNING
!
WARNING INDICATES YOU CAN BE KILLED OR
SERIOUSLY INJURED IF THE SAFETY INSTRUC-
TIONS THAT FOLLOW THIS SIGNAL WORD ARE
NOT OBEYED.
DANGER
!
DANGER INDICATES YOU WILL BE KILLED OR
SERIOUSLY INJURED IF THE SAFETY INSTRUC-
TIONS THAT FOLLOW THIS SIGNAL WORD ARE
NOT OBEYED.
CAUTION
!
CAUTION INDICATES YOU CAN OR YOUR EQUIP-
MENT CAN BE HURT IF THE SAFETY INSTRUC-
TIONS THAT FOLLOW THIS SIGNAL WORD ARE
NOT OBEYED.
IMPORTANT
INDICATES HELPFUL INFORMATION FOR PROP-
ER ASSEMBLY, OPERATION, OR MAINTENANCE
OF YOUR ENGINE.

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
PRECAUTIONS
WARNING:
FUEL FILLING PRECAUTIONS
• FUEL AND FUEL VAPORS ARE HIGHLY FLAMMA-
BLE.
• NEVER FILL GAS TANK INDOORS OR IN A POORLY
VENTILATED AREA.
• TURN ENGINE OFF AND LET COOL BEFORE RE-
MOVING GAS CAP.
• DO NOT OVERFILL GAS TANK. IF FUEL SPILLAGE
OCCURS, WIPE AWAY CAREFULLY AND ALLOW
FUEL TO DRY BEFORE STARTING ENGINE.
• PREVENT FIRE AND EXPLOSION CAUSED BY STAT-
IC ELECTRIC DISCHARGE. USE ONLY NON-METAL,
PORTABLE FUEL CONTAINERS APPROVED BY
THE UNDERWRITER’S LABORATORY(U.L.) OR THE
AMERICAN SOCIETY FOR TESTING & MATERIALS
(ASTM).
• NEVER POUR FUEL OUT OF ENGINE GAS TANK.
• NEVER ALLOW CHILDREN TO FILL THE GAS TANK.
ADULTS ONLY.
• NEVER ALLOW YOURSELF, OR ANYONE UNDER
THE INFLUENCE OF DRUGS OR ALCOHOL,TO FILL
GAS TANK.
• GAS CAP MUST BE PROPERLY SECURED BEFORE
AND DURING OPERATION.
• REFRAIN FROM SMOKING AND STAY AWAY FROM
OPEN FLAMES AND SPARKS WHEN REFUELING.
!
WARNING:
EXHAUST PRECAUTIONS
• DO NOT INHALE EXHAUST FUMES.THEY GIVE OFF
CARBON MONOXIDE, AN ODORLESS, COLORLESS,
DEADLY GAS.
• USE EXTREME CARE WHEN RUNNING ENGINE
NEAR PEOPLE OR ANIMALS. ALWAYS POINT EX-
HAUST AND MUFFLER IN A SAFE DIRECTION.
• NEVER RUN ENGINE IN AN ENCLOSED OR PAR-
TIALLY ENCLOSED AREA. EXAMPLES INCLUDE:
BUILDINGS THAT ARE ENCLOSED ON ONE OR
MORE SIDES, CAR PORTS OR BASEMENTS.
• ALWAYS MAKE SURE EXHAUST PIPE IS FREE OF
FOREIGN OBJECTS.
!
WARNING:
FIRE & BURN PROTECTION
• KEEP ALL SPARKS, SMOKING MATERIALS, AND
OPEN FLAMES AWAY FROM ENGINE.
• DO NOT USE ENGINE AROUND DRY BRUSH, CLOTH
RAGS, OR OTHER FLAMMABLE MATERIALS.
• BE CAREFUL OF HOT PARTS. THE MUFFLER
GUARD AND OTHER PARTS BECOME EXTREMELY
HOT DURING AND IMMEDIATELY AFTER USE. HOT
PARTS CAN CAUSE SEVERE BURNS.
• ALWAYS KEEP MATERIALS AND DEBRIS CLEAR
OF MUFFLER GUARD AND OTHER HOT ENGINE
PARTS.
• NEVER OPERATE THE ENGINE WITHOUT THE MUF-
FLER GUARD IN PLACE.
!
WARNING:
OTHER SAFETY PRECAUTIONS
• STAY AWAY FROM ROTATING PARTS. PLACE PRO-
TECTIVE COVERS OVER ROTATING PARTS.
• DO NOT CARRY OR REMOVE ENGINE WHILE IN OP-
ERATION.
• OPERATE THE ENGINE ONLY ON LEVEL AND STA-
BLE SURFACES.
!
WARNING:
ENGINE REPAIR PRECAUTIONS
• BEFORE WORKING ON ENGINE, ENGINE SHOULD
BE OFF AND COOL.
• ALWAYS DISCONNECT THE SPARK PLUG WIRE
FROM THE SPARK PLUG.
• SECURE DISCONNECTED SPARK PLUGWIRE AWAY
FROM SPARK PLUG AND ANY METAL OBJECTS
TO AVOID ARCING (HAZARDOUS UNINTENTIONAL
CONNECTION).
• CHECK ALL PARTS THAT WERE REPAIRED OR RE-
MOVED TO ENSURE SECURE AND PROPER FIT.
• USE ONLY ORIGINAL VIPER EQUIPMENT AND
PARTS.
!

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
ENGINE COMPONENTS
MODEL 60365 6.5 HP HORIZONTAL SHAFT
This is a 4-stroke air cooled engine. The 6.5 hp engine utilizes a
horizontal shaft and an oil slinger with dipstick.
WARNING
!
DO NOT REFUEL WHILE SMOKING, NEAR OPEN
FLAME, OR OTHER POTENTIAL HAZARDS.
FUEL IS HIGHLY FLAMMABLE AND MUST BE HAN-
DLED WITH CARE. NEVER FILL THE TANK WHEN
THE ENGINE IS HOT OR RUNNING. ALWAYS MOVE
OUTDOORS TO FILL THE TANK.
IMPORTANT
ENGINE IS SHIPPED FROM FACTORY WITHOUT
OIL. YOU MUST ADD ENGINE OIL BEFORE START-
ING ENGINE. IF ENGINE IS STARTED WITHOUT
OIL, ENGINE MAY BE DAMAGED BEYOND REPAIR
AND WILL NOT BE COVERED BY WARRANTY.
Spark Plug
Muffler
Gas Tank Gas Cap
Air Cleaner
Recoil
Pull-Start Handle
Choke
Oil Drain Plug
Oil Fill Gauge
Fuel Shut-Off

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
PRE-OPERATION PROCEDURES
PRE-OPERATION INSPECTION
1. Examine underneath and around engine for signs of oil or fuel
leaks.
2. Inspect fuel hoses and joints for tightness and fuel seepage.
3. Look for signs of engine damage.
4. Check that all guards and shields are in place, and all screws,
nuts and bolts are tightened.
5. Eliminate excessive debris around muffler and recoil starter.
6. Inspect the air filter component for air restrictions that may
reduce engine performance.
CAUTION
!
FOR THE SAFETY OF THE USER, AND TO MAXI-
MIZE THE LIFE OF THE ENGINE, IT IS CRUCIAL TO
TAKE TIME TO CHECK THE CONDITION OF THE
ENGINE. PROBLEMS MUST BE CORRECTED BE-
FORE OPERATING.
AVOID INJURY! ENGINE OIL IS HAZARDOUS TO
YOUR HEALTH. DISPOSE OF OIL APPROPRIATELY.
USE A SAFE DISPOSAL/RECYCLING CENTER.
WARNING
!
DO NOT ATTEMPT TO START ENGINE IN THE FOL-
LOWING WAYS:
• DO NOT USE STARTING FLUID.
• DO NOT SPRAY FLAMMABLE LIQUIDS OR VA-
PORS INTO AIR CLEANER, CARBURETOR OR
SPARK PLUG CHAMBER.
• DO NOT REMOVE SPARK PLUG AND PULL
ON STARTER ROPE. FLAMMABLE FUEL CAN
SPRAY OUT AND IGNITE FROM A SPARK FROM
SPARK PLUG.
DO NOT REFUEL WHILE SMOKING, NEAR OPEN
FLAME, OR OTHER POTENTIAL HAZARDS.
FUEL IS HIGHLY FLAMMABLE AND MUST BE HAN-
DLED WITH CARE. NEVER FILL THE TANK WHEN
THE ENGINE IS HOT OR RUNNING. ALWAYS MOVE
OUTDOORS TO FILL TANK.
IMPORTANT
ENGINE IS SHIPPED FROM FACTORY WITHOUT
OIL. YOU MUST ADD ENGINE OIL BEFORE START-
ING ENGINE.

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
CHECKING & ADDING OIL
Be sure the engine is located on a level surface before checking or
refilling oil.
1. Clean around oil fill area. SEE FIGURE 1.
2. Slide out dipstick and wipe clean with cloth. SEE FIGURE 2.
3. Reinsert and tighten dipstick.
4. Slide out dipstick and check oil.
5. If oil level is below the top thread of the oil fill hole, refill to upper
level. SEE FIGURE 3(a) & 3(b).
6. Change oil if contaminated. (See Chapter 5 Under “LUBRICA-
TION”.)
Viper engine oil may be put in through the oil dipstick hole or
through the oil fill plug opening. If an oil plug is present, loosen
screw and fill oil until oil level is even with top thread in plug hole.
CHECKING & FILLING GAS TANK
Be sure the engine is located on a level surface before checking or
refilling oil. Use unleaded regular, unleaded premium, or reformu-
lated automotive fuels only. Fuel may contain up to 10% ethanol,
10% gasohol, 15% MTBE, and 15% ETBE. DO NOT use Metha-
nol or leaded fuels. DO NOT mix oil with fuel.
1. Make sure engine is cool and not operating while filling.
2. Remove gas cap with inlet facing upward; fill to upper level.
Note: Do not overfill. Fill to roughly 1 ½ inches below the
neck to allow for fuel expansion.
3. Replace cap and remove any spilled fuel before operating.
WARNING
FUEL IS HIGHLY FLAMMABLE AND MUST BE HAN-
DLED WITH CARE. NEVER FILL THE TANK WHEN
THE ENGINE IS HOT OR RUNNING. ALWAYS MOVE
OUTDOORS TO FILL THE TANK.
!
FIGURE 1
FIGURE 2
FIGURE 3(a) FIGURE 3(b)
drain plug
oil fill hole
dipstick
top thread
upper level

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
ENGINE OPERATION
REVIEW SECTION “PRE-OPERATION INSPECTION” BEFORE
STARTING ENGINE.
STARTING & STOPPING ENGINE
MANUAL START ENGINE
1. Move engine to a well ventilated area, always outdoors, to pre-
vent carbon monoxide poisoning.
2. Move to an area away from flames or sparks, to avoid ignition of
vapors if present.
3. Remove all debris from air cleaner holes and gas cap to ensure
proper air flow.
4. Choke:
• “Full choke” position is established by moving the choke
lever as far left to the CHOKE position as possible. SEE
FIGURE 5.
• “Half choke” position is established when the choke lever is
maneuvered half-way between CHOKE and RUN positions.
SEE FIGURE 6.
First Start & Cold Start: Move choke lever to “full choke.”
SEE FIGURE 5.
Warm Start: “No choke” or “half choke” is needed. SEE
FIGURE 7.
WARNING
!
CARBON MONOXIDE GAS IS TOXIC. INHALATION
CAN CAUSE UNCONSCIOUSNESS AND DEATH.
NEVER LEAVE ENGINE RUNNING WHILE UNAT
-
TENDED.
DO NOT ATTEMPT TO START ENGINE IN THE FOL-
LOWING WAYS:
• DO NOT USE STARTING FLUID.
• DO NOT SPRAY FLAMMABLE LIQUIDS OR VA-
PORS INTO AIR CLEANER, CARBURETOR OR
SPARK PLUG CHAMBER.
• DO NOT REMOVE SPARK PLUG AND PULL
ON STARTER ROPE. FLAMMABLE FUEL CAN
SPRAY OUT AND IGNITE FROM A SPARK FROM
SPARK PLUG.
CAUTION
!
DO NOT STOP ENGINE BY MOVING CHOKE CON-
TROL TO CHOKE. BACKFIRE, ENGINE DAMAGE,
OR FIRE MAY OCCUR.
FIGURE 6 FIGURE 7FIGURE 5
“FULL CHOKE”
position
“HALF CHOKE”
position “NO CHOKE”
position

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
5. Grasp starter handle and pull out slowly, until resistance is felt.
Without letting it retract, pull rope with a rapid full arm stroke. Let
it return to its original position very slowly. Repeat this step each
time the starter rope is pulled. SEE FIGURE 8.
6. Pull recoil until engine fires or runs.
7. After engine begins operating, move choke lever to “half
choke.” SEE FIGURE 6.
8. Run engine for 30 to 45 seconds at “half choke” position until
engine warms up.
9. Move choke lever to “no choke” position and move throttle to
desired speed. SEE FIGURE 7.
ELECTRIC START ENGINE
1. Repeat steps 1-4 under “MANUAL START ENGINE” heading
on previous page.
2. Insert key and turn to start. SEE FIGURE 9.
3. After engine starts running, move choke lever to “half choke.”
SEE FIGURE 6.
4. Run engine for 30 to 45 seconds at “half choke” position until
engine warms up.
5. Move choke lever to “no choke” position and move throttle to
desired speed. SEE FIGURE 7.
6. To stop, turn key to OFF position. SEE FIGURE 10.
FIGURE 8
FIGURE 9
FIGURE 10
starter handle
“START”
position
“OFF”
position

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
MAINTENANCE
Please read the maintenance schedule, and observe these recom-
mended care operating intervals to extend the life of your engine.
MAINTENANCE SCHEDULE
CAUTION
!
TO PREVENT ACCIDENTAL STARTING:
AVOID INJURY! ENGINE MUST BE TURNED OFF
AND COOL AND SPARK PLUG WIRE MUST BE RE-
MOVED FROM SPARK PLUG BEFORE CHECKING
AND ADJUSTING ENGINE OR EQUIPMENT.
AVOID INJURY! TEMPERATURE OF MUFFLER AND
NEARBY AREAS MAY EXCEED 150° F (65° C).
AVOID THESE AREAS.
AVOID INJURY! CHECK ENGINE OFTEN FOR
LOOSE NUTS AND BOLTS. KEEP THESE ITEMS
TIGHTENED.
MAINTENANCE ITEM
Every 8 hours
(daily)
Every 50 hours
or seasonally
Every 100 hours
or seasonally Yearly
Clean Engine and
Check Bolts & Nuts
X
Engine Oil Check X
(See Lubrication section) Change * (initial 5 hours) X
Oil in Gear Reduction
(if equipped)
Change X
Air Filter Check X X
(See Air Filter section) Clean ** (20 hours)
Replace X
Spark Plug (Gap .030”) Check-Adjust X
(See Spark Plug section) Replace X
Fuel Filter Clean *** X
(See Fuel Filter section) Replace
Gas Tank Replace X
Clean *** X
Valve Clearance -
Intake: 0.15 mm (0.006”)
Exhaust: 0.20 mm (0.008”)
Check-Adjust X
* Perform initial oil change after first 5 hours of operation, then every 50 hours or every season
** Service more frequently under dusty conditions
*** These items should only be performed by a mechanically proficient person or by the servicing dealer

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
ENGINE MAINTENANCE
LUBRICATION
Choose engine oil that meets or surpasses the latest API service
classification. For temperatures higher than 32º F, use SAE 30 or
SAE 10W-30 motor oil. Use SAE 5W-30 or SAE 10W if tempera-
tures are below 32º F.
NOTE: Do not use SAE 10W-40 motor oil.
OIL MAINTENANCE
After the first five hours of operating a new Viper engine the oil
should be replaced, and every 50 hours of operating time thereaf-
ter. The oil should be changed every 25 hours if used under severe
conditions, such as in high temperatures or under heavy loads,
otherwise changed weekly. Check oil periodically; do not overfill!
CHANGING OIL
Be sure the engine is not operating and is located on a level
surface before checking or refilling oil. Engine should be warm for
easy removal of oil.
1. Detach spark plug wire and move away from spark plug. If
engine uses a battery; disconnect at negative terminal. SEE
FIGURE 11.
2. Disconnect oil drain plug and empty oil into suitable oil contain-
er. Dispose of oil properly. SEE FIGURE 1.
3. Reconnect drain plug. Remove dipstick (if applicable) or oil fill
cap. SEE FIGURE 2.
4. Fill with appropriate oil to “FULL” or top line of dipstick; other-
wise to top thread of oil fill hole. SEE FIGURE 3(a) & 3(b).
5. Reinsert dipstick or oil fill cap and tighten.
AIR FILTER
• Never run engine without air filter properly installed. Added
wear and engine failure may occur if air filter is not installed on
engine. SEE FIGURE 12.
• Service air filter every 3 months or after 20 hours of operation.
Clean filter daily in extremely dusty conditions.
REMOVING/INSTALLING AIR FILTER
1. Loosen wing nut and remove air cleaner cover by rotating to the
left towards spark plug. SEE FIGURE 12.
NOTE: Remove with care to prevent damage to choke
lever.
CAUTION
!
TO PREVENT ACCIDENTAL STARTING
AVOID INJURY! ENGINE MUST BE TURNED OFF
AND COOL AND SPARK PLUG WIRE MUST BE RE-
MOVED FROM SPARK PLUG BEFORE CHECKING
AND ADJUSTING ENGINE OR EQUIPMENT.
OIL IS HAZARDOUS WASTE
AVOID INJURY! ENGINE OIL IS HAZARDOUS TO
YOUR HEALTH. DISPOSE OF OIL APPROPRIATELY.
USE A SAFE DISPOSAL/RECYCLING CENTER.
FIGURE 11
FIGURE 12)
air filter cover
wing nut
spark plug
spark plug
wire

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
2. Remove foam pre-cleaner, followed by the air filter. SEE FIG-
URE 13(a) & 13(b).
3. Replace foam pre-cleaner and reinstall new or clean air filter
inside cover.
4. Place cover’s tabs into slots in bottom of base.
5. Replace cover and tighten wing nut. SEE FIGURE 14.
WASHING AIR FILTER
1. Wash in warm water with mild soap until dirt and debris are
removed. Press filter when washing, do not twist.
2. Rinse in warm water until soap and dirt are removed.
3. Dry filter by wrapping in a clean cloth and pressing filter until it is
dry.
4. Attach the filter and air cleaner cover to the engine.
SPARK PLUG
The recommended spark plug is a Torch F7RTC which cross refer-
ences to an AC Delco R42CXLS, Champion RN7YC or Denso
W22EPR-U.
CHECKING AND CHANGING SPARK PLUG
1. Check spark plug every 50 operating hours.
2. Disconnect the spark plug cap, and clean any debris form
around the spark plug area.
3. Remove spark plug and replace if any of the following occur;
pitted electrodes, burned electrodes, cracked porcelain, or de-
posits around electrodes.
4. After analysis, seat spark plug and tighten with spark plug
wrench to compress the sealing washer. SEE FIGURE 11.
• Reinstall original spark plug, tighten additional 1/2 turn.
• Installing new spark plug, adjust spark plug gap to .030” and
tighten additional 1/8 – 1/4 turn .
NOTE: Loose spark plug may overheat and damage
engine. Over tightened spark plug may damage threads in
the cylinder head.
SPARK PLUG MAINTENANCE
Spark plug should be removed, cleaned and gap adjusted after ap-
proximately fifty hours of operating time.
NOTE: A sand blaster should not be used to clean spark
plugs. Microscopic particles remaining in the plug may
score the engine cylinder during operation. Use solvent
and a wire brush to clean the plug and compressed air to
blow out completely.
CARBURETOR
• Never tamper with factory setting of the carburetor.
• Contact your service provider or Ardisam, Inc. if adjustment is
needed.
WARNING
!
FUEL IS HIGHLY FLAMMABLE AND MUST BE HAN-
DLED WITH CARE. NEVER FILL THE TANK WHEN
THE ENGINE IS HOT OR RUNNING. ALWAYS MOVE
OUTDOORS TO FILL GAS TANK.
FIGURE 13(a)
FIGURE 13(b)
FIGURE 14
foam pre-cleaner
air filter
filter cover

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
FUEL FILTER
CLEANING OR REPLACING FUEL FILTER
1. Drain fuel from tank before attempting to clean/replace fuel filter.
2. Disconnect the hose clamp and remove fuel filter from fuel pipe.
SEE FIGURE 15(a) & 15(b).
3. Filter may be washed with kerosene.
4. Reassemble; if filter is overly dirty replace with new.
BATTERY (ELECTRIC MODELS ONLY)
Viper engines use a 12 V 7.0 AH/20HR battery. Never connect
the battery in reverse polarity avoiding a short circuit to the battery
charging system. Always connect the positive (+) battery cable
to the battery terminal before hooking up the negative (-) battery
cable.
CONNECTION
1. Connect positive (+) battery cable to the starter solenoid termi-
nal.
2. Connect negative (-) battery cable to an engine mounting bolt,
frame bolt, or other proficient ground connection.
3. Connect positive (+) battery cable to the positive (+) battery
terminal.
4. Connect negative (-) battery cable to the negative (-) battery
terminal.
5. Coat both terminals and cable ends with grease.
FUSE REPLACEMENT
Viper’s electric starter relay circuit and battery charging circuit are
protected by a 5-ampere fuse. The electric starter is inoperable if
the fuse burns out. The engine may be started manually without a
fuse, but the battery will not charge while operating until the fuse is
replaced.
1. Remove ignition circuit cover and locate fuse housing. SEE
FIGURE 16(a) & 16(b).
WARNING
!
BATTERY MAY EXPLODE
• BATTERY MAY EXPLODE IF PROPER PROCE-
DURE IS NOT FOLLOWED, CAUSING SERIOUS
HARM TO PEOPLE NEARBY.
• KEEP AWAY FROM ALL SPARKS, OPEN
FLAMES, AND SMOKING MATERIALS
FIGURE 15(a)
FIGURE 15(b)
FIGURE 16(b)
fuel pipe hose clamp
fuel filter
fuse housing
FIGURE 16(a)
ignition
circuit
cover

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
2. Open the fuse cover and examine the fuse. If fuse is burnt out,
SEE FIGURE 17.
3. Pull out and dispose burnt-out fuse. Install a new 5-ampere
fuse. SEE FIGURE 18.
4. Replace ignition circuit cover. SEE FIGURE 19(a) & 19(b).
NOTE: Repeated fuse failure suggests a short circuit or an
overload in the electrical system. Service engine at nearest
Viper dealer.
TRANSPORTING AND STORAGE
TRANSPORTING ENGINE
1. Never transport engine inside an enclosed space or vehicle.
Fuel or fuel vapors may ignite causing serious injury or death.
2. If fuel is present in the gas tank remove fuel or transport with an
open vehicle in an upright position.
3. If an enclosed vehicle must be used, remove gas into an ap-
proved red fuel container. DO NOT siphon by mouth.
4. Run engine to use up the fuel in the carburetor and gas tank.
Always run engine in a well ventilated area.
5. Wipe away any spilled fuel from engine. Allow to dry.
STEPS FOR LONG TERM STORAGE
1. Add fuel stabilizer according to manufacturer’s instructions.
2. Run engine for 10-15 minutes to ensure that the stabilizer
reaches the carburetor.
3. Remove the remainder of the fuel from the gas tank into an ap-
proved fuel container.
4. Store engine in its upright position.
5. Remove all debris from engine.
WARNING
!
FAILURE TO FOLLOW MAINTENANCE INFORMA-
TION CAN CAUSE DEATH OR SERIOUS INJURY.
DO NOT REMOVE FUEL WHILE SMOKING, NEAR
OPEN FLAME, OR OTHER POTENTIAL HAZARDS.
AVOID INJURY! NEVER STORE ENGINE WITH
FUEL IN THE TANK INSIDE A BUILDING. POTEN-
TIAL SPARKS MAY BE PRESENT CAUSING IGNI-
TION OF FUEL AND FUEL VAPORS.
CAUTION
!
AVOID INJURY! TO AVOID INJURY OR DEATH, NEV-
ER SIPHON FUEL BY MOUTH.
AVOID INJURY! CHECK ENGINE OFTEN FOR
LOOSE NUTS AND BOLTS. KEEP THESE ITEMS
TIGHTENED.
FIGURE 17
FIGURE 18 FIGURE 19(a) FIGURE 19(b)
fuse cover
fuse

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OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
SERVICE AND TROUBLESHOOTING
SERVICE INFORMATION
At Ardisam, we build quality and durability into the design of our
products. Nevertheless, no amount of careful design by us, or thor-
ough maintenance by you, can guarantee a repair-free life for your
engine. Most repairs will be minor and easily fixed by following the
suggestions in the troubleshooting guide of this section.
This section will help you pinpoint the causes of common problems
and identify remedies.
For more complicated repairs you may want to rely on your retailer,
an authorized mechanic or Ardisam, Inc. (contact your retailer
for a list of authorized mechanics in your area). A parts catalog
is included in this section. We will always be glad to answer any
questions you encounter or find suitable assistance to meet your
needs. To order parts or inquire about our warranty call, write or
browse our website at the address found below under the section
“ordering repair parts.”
ORDERING REPAIR PARTS
Parts can be obtained from the store where your engine was pur-
chased or direct from the factory. To order from the factory, call or
write to:
Ardisam, Inc.
1360 First Avenue, Cumberland, WI 54829
Phone [phone] Fax [phone]
1-800-345-6007
Email: [e-mail]
www.ardisam.com
Please include the following information with your order:
1. Part numbers
2. Part description
3. Quantity
4. Model number and serial number
CAUTION
!
PRACTICE SAFETY AT ALL TIMES. ENGINE MUST
BE TURNED OFF AND ALLOWED TO COOL AND
SPARK PLUG WIRE MUST BE DISCONNECTED
BEFORE ATTEMPTING ANY MAINTENANCE OR
REPAIR.

ENGINES
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.com
Ardisam, Inc. Page 16
800-345-6007
OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE REMEDY/ACTION
Engine will not start 1. Power switch off 1. Flip switch to ON position
2. Spark plug wire disconnected 2. Connect spark plug wire to spark plug
3. Out of fuel 3. Refuel
4. Spark plug wet, faulty or improperly
gapped
4. Clean, replace or gap sparkplug
Electric Start 5. Battery discharged 5. Recharge battery
6. Fuse burnt out 6. Replace fuse
Engine runs rough, floods during opera-
tion
1. Dirty air filter 1. Clean or replace air filter
2. Choke partially engaged 2. Turn off choke
3. Carburetor out of adjustment 3. Call factory
Engine is hard to start 1. Stale fuel 1. Drain old fuel and replace with fresh.
Use gas stabilizer at end of season
2. Spark plug wire loose 2. Make sure spark wire is securely at-
tached to spark plug
3. Dirty carburetor 3. Clean carburetor, use gas stabilizer,
new gas can
Engine misses or lacks power 1. Clogged gas tank 1. Remove and clean
2. Clogged air filter 2. Clean or replace
3. Improper carburetor adjustment 3. Call factory
4. Spark plug dirty, improper gap, or
wrong type
4. Replace spark plug and adjust gap to
.030”
Engine runs, then quits 1. Gas cap not venting 1. Open self venting gas cap
Contact service provider if above remedies fail.

ENGINES
ARDISAM
.com
Ardisam, Inc. Page 17
800-345-6007
OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
6.5 HP VIPER ENGINE PARTS EXPLOSION
31
22
2
1
12
19
32
21
20
20
37
38
37
38
8
34
35
36
28 29 25
26
27
13
18
17
6
16
15
14
5
7
9
10
3
11
4
30
39
33
30

ENGINES
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.com
Ardisam, Inc. Page 18
800-345-6007
OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
6.5 HP VIPER ENGINE PARTS LIST
REF
NO.
PART
NO. DESCRIPTION QTY.
1 64686 MUFFLER KIT 1
2 64304 GAS TANK 1
3 64283 HOUSING, AIR CLEANER 1
4 64237 FAN HOOD ASSEMBLY 1
5 64285 BASE, AIR FILTER 1
6 64279 COVER, AIR CLEANER 1
7 64308 CARBURETOR ASSEMBLY 1
8 64207 STUD BOLT, M6 X 113 2
9 64309 GASKET, AIR CLEANER 1
10 64204 AIR DUCT 1
11 64732 NUT, FLANGED M6 2
12 64291 NUT, FLANGED M8 2
13 64274 NUT, FLANGED M14 1
14 64733 SCREW, FLAT HEAD 2
15 64286 HOLDER, AIR FILTER 1
16 64280 AIR FILTER ELEMENT 1
17 64281 WASHER 1
18 64278 WING NUT 1
19 64294 GASKET, EXHAUST 1
20 64182 DIPSTICK ASSEMBLY 2
21 4352 KEY 1
22 6327 GAS CAP W/ PACKING RING 1
REF
NO.
PART
NO. DESCRIPTION QTY.
25 64277 FLYWHEEL 1
26 64276 FAN, FLYWHEEL 1
27 64275 STARTING FLANGE 1
28 64273 IGNITION COIL ASSEMBLY 1
29 64269 BOLT, M6 X 25 FLANGED 2
30 6272 BOLT, M6 X 18 FLANGED 4
31 6263 BOLT, M6 X 12 FLANGED 3
32 64212 SPARK PLUG 1
33 64250 RECOIL STARTER ASSEMBLY
(INCLUDES PULL-START HANDLE)
1
34 64305 GASKET, INLET 1
35 64306 CONNECTING BLOCK 1
36 64307 GASKET, CARBURETOR 1
37 6204 OIL DRAIN PLUG 2
38 64157 WASHER 2
39 64249 PULL-START HANDLE 1

ENGINES
ARDISAM
.com
Ardisam, Inc. Page 19
800-345-6007
OPERATING AND MAINTENANCE INSTRUCTIONS
6.5 hp 4-Stroke Engine
REGISTRATION
Record your model number and serial number in the space
provided for easy reference. Fill out and mail the registration
card located in your parts packet. Warranty is valid only if your
completed registration card is received by Ardisam, Inc., at time
of purchase.
Model Number
Serial Number
Date of Purchase
Place of Purchase
Ardisam, Inc.
1360 First Avenue
Cumberland, Wisconsin 54829
800-345-6007 · Fax [phone]
Email: [e-mail]
WARRANTY
Ardisam, Inc., Manufacturing Company warrants this Viper
engine under a two year limited warranty to be free from defects
in materials and workmanship for the service life of the product
not to exceed twenty four consecutive months from the date of
purchase for consumer applications and one year for all com-
mercial applications. As an Ardisam Viper small engine owner,
you are accountable for executing proper maintenance listed
in your Operating and Maintenance Instructions. This warranty
applies to the original owner with a proof of purchase and is not
transferable. This warranty applies only to products which have
not been subjected to negligent use, misuse, alteration, accident,
unauthorized parts, failure to use proper fuel and oil, or if repairs
have been performed at non-authorized service centers. This
warranty supersedes all other warranties either expressed or
implied and all other obligations or liabilities on our part. Ardisam,
does not assume, and does not authorize any other person to
assume for us, any liability in connection with the sale of our
products. Warranty work must be sent directly to Ardisam, Inc.
or one of our authorized service centers and performed by them.
To obtain warranty service and replacement instructions, contact
our customer service department at 800-345-6007 or by writing
to: Ardisam, Inc., 1690 Elm Street, Cumberland, WI 54829. All
items must be shipped prepaid. Ardisam will at no charge, repair
or replace, at their discretion, any defective part which falls under
the conditions stated above. Ardisam retains the right to change
models, specifications and price without notice.

VIPER Engines, Manufactured by Ardisam, Inc.
1360 First Avenue
Cumberland, Wisconsin 54829
800-345-6007 · Fax [phone]
Email: inf[email protected]
ARDISAM
.com