Yamaha MX-800 User manual

Printed in China
2016.06×1 !
(E, F, S) LIT-19626-02-41
MX775
MX800
MX825
EOWNER’S MANUAL
FMANUEL DU PROPRIÉTAIRE
ES MANUAL DEL PROPIETARIO
Read this manual carefully before
operating this machine.
Il convient de lire attentivement ce
manuel avant la première utilisation de
la machine.
Lea este manual atentamente antes de
utilizar este equipo.
7UD-F8199-61
7UD-F8199-60_1_cover_4mm.indd 1 2016/06/14 13:09:22

7UD-F8199-60_1_cover_4mm.indd 2 2016/06/14 13:09:22

Read this manual carefully before
operating this machine.
OWNER’S MANUAL
MX775
MX800
MX825
LIT-19626-02-41 7UD-F8199-61-E0
7UD-F8199-61-1E0.book 1 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

Cover page 2
Read this manual carefully before operating this machine. This manual should
stay with this machine if it is sold.
7UD-F8199-61-1E0.book 1 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

Introduction
Congratulations on your purchase of your new Yamaha.
This manual will provide you with a good basic understanding of the operation and main-
tenance of this machine.
If you have any questions regarding the operation or maintenance of your machine,
please consult a Yamaha dealer.
TIP
• Yamaha continually seeks advancements in product design and quality.
Therefore, while this manual contains the most current product information available at
the time of printing, there may be minor discrepancies between your machine and this
manual. If there is any question concerning this manual, please consult a Yamaha
dealer.
• This manual should be considered a permanent part of this machine and should
remain with this machine when resold.
* Product and specifications are subject to change without notice.
PLEASE READ AND UNDERSTAND THIS MANUAL COMPLETELY BEFORE OPER-
ATING THE MACHINE.
WARNING
MX775, MX800, MX825
OWNER’S MANUAL
©2016 by Yamaha Motor Corporation, U.S.A.
1st Edition, June 2016
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation, U.S.A.
is expressly prohibited.
Printed in China
P/N LIT-19626-02-41
7UD-F8199-61-1E0.book 1 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

Important manual information
Particularly important information is distinguished in this manual by the following nota-
tions.
This is the safety alert symbol. It is used to alert you to potential personal injury
hazards. Obey all safety messages that follow this symbol to avoid possible injury
or death.
A WARNING indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
A NOTICE indicates special precautions that must be taken to avoid damage to the
machine or other property.
A TIP provides key information to make procedures easier or clearer.
WARNING
NOTICE
TIP
7UD-F8199-61-1E0.book 2 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

Contents
Safety information.................... 1
General safety information .................. 1
Exhaust fumes are poisonous............. 1
Fuel is highly flammable and
poisonous............................................ 1
Engine and muffler may be hot ........... 3
Electric shock prevention .................... 4
High-pressure fluids ............................ 4
Accidental engine start prevention ...... 4
Rotating parts...................................... 4
Location of important labels ................ 5
Controls and features .............. 6
Description .......................................... 6
General view.................................... 6
Before operation....................... 7
Preparation.......................................... 7
Engine oil ......................................... 7
Pre-operation check ............................ 8
Pre-operation check......................... 8
Operation................................... 9
Precautions for use ............................. 9
Periodic maintenance ............ 10
The importance of maintenance........ 10
Maintenance schedule ...................... 10
Maintenance chart ......................... 10
Spark plug inspection........................ 12
Engine oil replacement...................... 13
Air filter .............................................. 15
Spark arrester (For models
equipped with a muffler).................... 16
Storage .................................... 18
Add fuel stabilizer.............................. 18
Engine............................................... 18
Troubleshooting ..................... 20
Engine won’t start.............................. 20
Specifications ......................... 22
MX775/MX800/MX825 ...................... 22
Consumer information ........... 23
Machine identification ....................... 23
Identification number records............ 23
Exhaust emission control
system and components ....... 24
Index ........................................ 25
7UD-F8199-61-1E0.book 1 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

1
Safety information
General safety information
• Do not allow children to operate the multi-purpose
engine.
• Do not place any obstacles on the multi-purpose
engine.
• Do not sit or stand on the multi-purpose engine.
Exhaust fumes are poisonous
• Using a multi-purpose engine indoors CAN KILL
YOU IN MINUTES. Multi-purpose engine exhaust
contains carbon monoxide. This is a poison you can-
not see or smell.
• NEVER use inside a home or garage, EVEN IF
doors and windows are open.
• Only use OUTSIDE and far away from windows,
doors, and vents.
Fuel is highly flammable and poison-
ous
• Always turn off the engine when refuelling.
• Never refuel while smoking or in the vicinity of an
open flame.
7UD-F8199-61-1E0.book 1 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

2
Safety information
• Take care not to spill any fuel on the engine or muf-
fler when refueling.
• Do not leave the multi-purpose engine inside the
vehicle or in the trunk.
• If you swallow any fuel, inhale fuel vapor, or allow any
to get in your eye(s), see your doctor immediately. If
any fuel spills on your skin or clothing, immediately
wash with soap and water and change your clothes.
• When refueling, do not place the fuel tank cap near
the muffler.
• When operating or transporting the machine, be sure
it is kept upright. If it tilts, fuel may leak from the
engine.
• When lifting the engine, use the engine hangers to
attach a winch or other suitable lifting device.
1
1
1. Engine hunger
7UD-F8199-61-1E0.book 2 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

3
Safety information
Engine and muffler may be hot
• Place the machine in a place where pedestrians or
children are not likely to touch the machine.
• Avoid placing any flammable materials near the
exhaust outlet during operation.
• In order to prevent overheating, ensure adequate air-
flow by keeping the machine at least 1 m (3 ft) from
objects or other equipment.
• Do not operate the engine with a dust cover or other
objects covering it.
7UD-F8199-61-1E0.book 3 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

4
Safety information
• When covering the multi-purpose engine, be sure to
do so only after the engine and muffler have com-
pletely cooled down.
Electric shock prevention
• Never operate the engine in rain or snow.
• Never touch the machine with wet hands or electrical
shock will occur.
High-pressure fluids
• High-pressure fluid leaks are highly toxic and hazard-
ous. High-pressure punctures the skin. Do not use
your hand to check for high-pressure hydraulic leaks.
Accidental engine start prevention
• To prevent the engine from accidentally starting, be
sure to stop the engine and remove the spark plug
caps before doing any service.
Rotating parts
• Keep hands, feet, hair and clothing away from the
rotating parts.
• Never operate the multi-purpose engine without
shroud, covers or guards.
7UD-F8199-61-1E0.book 4 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

5
Safety information
Location of important labels
Please read the following labels carefully before operating this machine.
TIP
Maintain or replace safety and instruction labels, as necessary.
1
2
CAN ICES-2/NMB-2
7CN-H2377-00
1
2
7UD-F8199-61-1E0.book 5 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

6
Controls and features
Description
General view
1 Spark plug 7 Fuel filter
2 Air filter case cover 8 Oil filter cartridge
3 Oil cooler 9 Oil drain bolt
4 Shroud 10 Muffler
(For models equipped with a muffler)
5 Fuel pump 11 Fuse
6 Oil filler cap
1
10
2
6
3
8
9911
1
4 5
7
4
7UD-F8199-61-1E0.book 6 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

7
Before operation
Preparation
Engine oil
1. Place the multi-purpose engine on a level surface.
2. Remove the oil filler cap.
3. Fill the specified amount of the recommended
engine oil.
4. Wipe the engine oil dipstick clean, insert it back
into the oil filler hole (without screwing it in), and
then remove it again to check the oil level.
The multi-purpose engine has been shipped with-
out engine oil. Do not start the engine until you
have filled it with the sufficient engine oil.
NOTICE
1
2
1. Oil filler cap
2. Engine oil dipstick
0˚C
SAE 5W
32˚F
25˚C
80˚F
YAMALUBE SAE 10W-30
Performance All Purpose
Be sure no foreign material enters the crankcase.
Recommended engine oil:
AYAMALUBE SAE 10W-30 Performance All
Purpose,
SAE 10W-30 or 10W-40
BSAE 5W-30
Recommended engine oil grade:
API Service SE type or higher
Engine oil quantity:
2.0 L (2.11 US qt, 1.76 Imp qt)
NOTICE
1. Minimum level mark
2. Maximum level mark
3. Engine oil dipstick
4. Oil filler cap
7UD-F8199-61-1E0.book 7 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

8
Before operation
TIP
The engine oil should be between the minimum and
maximum level marks.
5. Install and tighten the oil filler cap.
Pre-operation check
The condition of a multi-purpose engine is the owner’s
responsibility. Vital components can start to deteriorate
quickly and unexpectedly, even if the multi-purpose
engine is unused.
TIP
Pre-operation checks should be made each time the
multi-purpose engine is used.
Pre-operation check
• Fuel line
- Check fuel hose for crack or damage.
- Replace if necessary.
•Engineoil
- Check oil level in engine.
- If necessary, add recommended oil to specified
level. (See page 7 for more details.)
- Check multi-purpose engine for oil leakage.
• The point where abnormality was recognized by
use
- Check operation.
- If necessary, consult a Yamaha dealer.
If any item in the pre-operation check is not work-
ing properly, have it inspected and repaired before
operating the multi-purpose engine.
WARNING
7UD-F8199-61-1E0.book 8 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

9
Operation
Precautions for use
Never operate the engine in a closed area or it may
cause unconsciousness and death within a short
time. Operate the engine in a well ventilated area.
The multi-purpose engine has been shipped with-
out engine oil. Do not start the engine until you
have filled it with the sufficient engine oil.
WARNING
NOTICE
7UD-F8199-61-1E0.book 9 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

10
Periodic maintenance
The importance of maintenance
Safety is an obligation of the owner. Periodic inspection, adjustment and lubrication will
keep your multi-purpose engine in the safest and most efficient condition possible. The
most important points of multi-purpose engine inspection, adjustment, and lubrication are
explained on the following pages.
Maintenance schedule
Maintenance chart
If you are not familiar with maintenance work, have a Yamaha dealer do it for you.
Stop the engine before starting maintenance work.
Use only Yamaha specified genuine parts for replacement. Ask an authorized
Yamaha dealer for further information.
Daily 50 hrs 100 hrs 200 hrs 250 hrs 500 hrs 1000
hrs
Check spark plug 
Check muffler and spark arrester (*1)
Check oil level 
Change engine oil 
Change oil filter cartridge 
Clean shrouds and cooling area 
Check and change fuel filter 
Check fuel line 
Clean oil cooler fins 
Check air filter element 
Replace air filter element 
Check air filter inner element 
Replace air filter inner element 
Check valve clearance (*2)
Clean combustion chamber (*2)
Idle speed (*2)
Fitting/fastener (*2)
WARNING
WARNING
NOTICE
7UD-F8199-61-1E0.book 10 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

11
Periodic maintenance
*1 For models equipped with a Yamaha muffler.
*2 Have a Yamaha dealer perform the service.
The point where abnormality was
recognized by use. 
Daily 50 hrs 100 hrs 200 hrs 250 hrs 500 hrs 1000
hrs
7UD-F8199-61-1E0.book 11 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

12
Periodic maintenance
Spark plug inspection
The spark plugs are important engine components,
which should be checked periodically.
1. Remove the spark plug caps and the spark plugs.
2. Check for discoloration and remove the carbon.
The porcelain insulator around the center elec-
trode of spark plug should be a medium-to-light tan
color.
3. Check the spark plug type and gap.
TIP
The spark plug gap should be measured with a wire
thickness gauge and, if necessary, adjusted to specifi-
cation.
4. Install the spark plugs and then tighten them.
TIP
If a torque wrench is not available when installing a
spark plug, a good estimate of the correct torque is
1/4–1/2 turn past finger tight. However, the spark plug
should be tightened to the specified torque as soon as
possible.
5. Install the spark plug caps.
1
1. Spark plug cap
1
1. Spark plug gap
Standard spark plug:
BPR6ES (NGK)
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Spark plug tightening torque:
20 N·m (2.0 kgf·m, 14 lb·ft)
7UD-F8199-61-1E0.book 12 ページ ２０１６年６月１４日 火曜日 午前１１時３９分

13
Periodic maintenance
Engine oil replacement
1. Place the multi-purpose engine on a level surface
and warm up the engine for several minutes. Then
stop the engine.
2. Remove the oil filler cap.
3. Place an oil pan under the engine. Remove the oil
drain bolt and gasket so that the oil can be com-
pletely drained.
TIP
Skip steps 4–6 if the oil filter cartridge is not being
replaced.
4. Remove the oil filter cartridge with an oil filter
wrench.
TIP
An oil filter wrench is available at a Yamaha dealer.
5. Apply a thin coat of clean engine oil to the O-ring of
the new oil filter cartridge.
TIP
Make sure that the O-ring is properly seated.
Avoid draining the engine oil immediately after
stopping the engine. The oil is hot and should be
handled with care to avoid burns.
WARNING
1
1. Oil filler cap
12
1. Oil drain bolt
2. Gasket
1 2
1. Oil filter wrench
2. Oil filter cartridge
1. O-ring
7UD-F8199-61-1E0.book 13 ページ ２０１６年６月１４日 火曜日 午前１１時３９分