8-65
8
EBU25741TroubleshootingAlthough Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the
fuel, compression, or ignition systems, for exam-
ple, can cause poor starting and loss of power.
The following troubleshooting charts represent
quick and easy procedures for checking these vi-
tal systems yourself. However, should your ATV
require any repair, take it to a Yamaha dealer,
whose skilled technicians have the necessary
tools, experience, and know-how to service the
ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWB02281Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-
lot lights from water heaters or furnaces. UBB561E0.book Page 65 Monday, March 26, 2018 11:15 AM
10-2
10
Cooling system:Liquid cooled
Valve train: SOHC
Number of cylinders:
Single cylinder
Displacement: 421 cm³
Bore × stroke:
84.5 × 75.0 mm (3.33 × 2.95 in)
Compression ratio:
10.0 : 1
Starting system: Electric starter
Lubrication system: Wet sumpEngine oil:Recommended brand:YAMALUBE
SAE viscosity grades: 5W-30, 10W-30, 10W-40, 15W-40, 20W-40, 20W-50 Recommended engine oil grade:
API service SG type or higher, JASO standard MA
Quantity: Oil change:2.30 L (2.43 US qt, 2.02 Imp.qt)
With oil filter removal: 2.40 L (2.54 US qt, 2.11 Imp.qt)
Final gear oil:Type:Yamaha Friction Modified Shaft Drive Gear Oil
Quantity: 0.38 L (0.40 US qt, 0.33 Imp.qt)Differential gear oil:Type:Yamaha Friction Modified Shaft Drive Gear Oil or SAE 80
API GL-4 Hypoid gear oil
Quantity: 0.35 L (0.37 US qt, 0.31 Imp.qt)0 10 30 50 70 90 110 130 F
–20 –10 0 10 20 30 40 50 CSAE 5W-30
SAE 10W-30
SAE 10W-40
SAE 15W-40
SAE 20W-40SAE 20W-50
UBB561E0.book Page 2 Monday, March 26, 2018 11:15 AM
