2015 YAMAHA GRIZZLY 550 tire size

2-3
2
technique described in this manual on level
ground. Avoid crossing the side of a steep hill if
possible.
 Always use proper procedures if you stall or roll
backwards when climbing a hill. To avoid stall-
ing, use the proper gear range and maintain a
steady speed when climbing a hill. If you stall or
roll backwards, follow the special procedure for
braking described in this manual. Dismount on
the uphill side or to a side if pointed straight up-
hill. Turn the ATV around and remount, following
the procedure described in this manual.
 Always check for obstacles before operating in
a new area.
 Never attempt to operate over large obstacles,
such as large rocks or fallen trees. Always follow
proper procedures when operating over obsta-
cles as described in this manual.
 Always be careful when skidding or sliding.
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smooth
terrain. On extremely slippery surfaces, such as
ice, go slowly and be very cautious in order to
reduce the chance of skidding or sliding out of
control. 
Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may have
reduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.
 Always be sure there are no obstacles or people
behind you when you operate in reverse. When
it is safe to proceed in reverse, go slowly.
 Always use the size and type of tires specified in
this manual.
 Always maintain proper tire pressure as de-
scribed in this manual.
 Never exceed the stated load capacity for an
ATV. Cargo should be properly distributed and
securely attached. Reduce speed and follow in-
structions in this manual for carrying cargo or
pulling a trailer. Allow greater distance for brak-
ing.
 Do not operate your ATV during darkness un-
less it is equipped with a properly functioning
headlight. Off-road riding is inherently danger-
ous and additionally, off-road trails do not have
streetlights to guide you.
U2LB61E0.book Page 3 Friday, February 21, 2014 3:03 PM

5-6
5Tire information
This ATV is equipped with tubeless tires with
valves.
WARNING
EWB02552Use of improper tires on this ATV may cause
loss of control, increasing your risk of an acci-
dent. After extensive tests, only the tires listed below
have been approved for this model by Yamaha
Motor Manufacturing Corporation of America.1. Tire wear limit
Front:Manufacturer/model:YFM550DF CHENG SHIN/C828
(AUS)(NZL)
YFM550DF MAXXIS/MU19
(EUR)(FRA)(GBR)
YFM550PF CHENG SHIN/C828
(AUS)(NZL)
YFM550PF MAXXIS/MU19
(EUR)(FRA)(GBR)
YFM550PHF MAXXIS/MU19
Size: AT25 x 8-12
Ty p e : Tu b e l e s s
Rear: Manufacturer/model:YFM550DF CHENG SHIN/C828
(AUS)(NZL)
YFM550DF MAXXIS/MU20
(EUR)(FRA)(GBR)
YFM550PF CHENG SHIN/C828
(AUS)(NZL)
YFM550PF MAXXIS/MU20
(EUR)(FRA)(GBR)
YFM550PHF MAXXIS/MU20
U2LB61E0.book Page 6 Friday, February 21, 2014 3:03 PM

5-7
5
Aftermarket tires and rims
The tires and rims that came with your ATV were
designed to match the performance capabilities
and to provide the best combination of handling,
braking, and comfort. Other tires, rims, sizes, and
combinations may not be appropriate.
EBU19841Chassis fastenersMake sure that all nuts, bolts and screws are
properly tightened.EBU19851Instruments, lights and switchesCheck that all instruments, lights and switches are
working properly. Correct if necessary. Size:
AT25 x 10-12
Ty p e : Tu b e l e s sU2LB61E0.book Page 7 Friday, February 21, 2014 3:03 PM

10-3
10
Transmission:Primary reduction system:V-belt
Secondary reduction system:
Shaft drive
Secondary reduction ratio: 41/21 × 24/18 × 33/9 (9.544)
Transmission type: V-belt automatic
Operation:
Left hand operation
Reverse gear: 23/14 × 28/23 (2.000)
Low range: 31/16 (1.938)
High range:
31/27 (1.148)Chassis:Frame type:Steel tube frame
Caster angle:
5.0 °
Trail: 26.0 mm (1.02 in)Front tire:Type:
Tubeless
Size: AT25 x 8-12 Manufacturer/model:
YFM550DF CHENG SHIN/C828 (AUS)(NZL)
YFM550DF MAXXIS/MU19 (EUR)(FRA)(GBR)
YFM550PF CHENG SHIN/C828 (AUS)(NZL)
YFM550PF MAXXIS/MU19 (EUR)(FRA)(GBR)
YFM550PHF MAXXIS/MU19
Rear tire:Type:Tubeless
Size:
AT25 x 10-12
Manufacturer/model: YFM550DF CHENG SHIN/C828 (AUS)(NZL)
YFM550DF MAXXIS/MU20 (EUR)(FRA)(GBR)
YFM550PF CHENG SHIN/C828 (AUS)(NZL)
YFM550PF MAXXIS/MU20 (EUR)(FRA)(GBR)
YFM550PHF MAXXIS/MU20Loading:Maximum loading limit:220.0 kg (485 lb)
(Total weight of rider, cargo, accessories, and tongue)Tire air pressure (measured on cold tires):Recommended:
Front: 35.0 kPa (0.350 kgf/cm², 5.0 psi)
Rear:
30.0 kPa (0.300 kgf/cm², 4.4 psi)
Minimum: Front:
32.0 kPa (0.320 kgf/cm², 4.6 psi)
Rear: 27.0 kPa (0.270 kgf/cm², 4.0 psi)
U2LB61E0.book Page 3 Friday, February 21, 2014 3:03 PM