2007 Yamaha Motorsports Nytro ER Owners Manual - Page 63

2007 Yamaha Motorsports Nytro ER Manual

Page 63 highlights

E_8gg.book Page 8 Thursday, March 16, 2006 4:23 PM ESU04860 Adjusting the high-altitude settings Operating at high altitude reduces the performance of a gasoline engine about 3% for every 305 m (1,000 ft) of elevation. This is because there is less air as altitude increases. Less air means less oxygen available for combustion. Your snowmobile can be adjusted to overcome most of the problems found in high-altitude riding. Carburetor adjustments are the most important. Less air at high altitude makes the air/fuel ratio too rich, which can cause poor performance. Common problems are hard starting, bogging, and plug fouling. Proper carburetion adjustments will correct the air/fuel ratio. Be sure to have a Yamaha dealer make these adjustments. Remember: Less air at higher altitude means there is less horsepower available, even with proper carburetion. Expect acceleration and top speed to be reduced at higher altitudes. To overcome operating with less power at high altitudes, your snowmobile may also require different settings for the drive chain gears and V-belt clutch to avoid poor performance and rapid wear. If you plan to operate your snowmobile at an altitude different from the area where you bought it, be sure to consult a Yamaha dealer. The dealer can tell you if there are any changes necessary for the altitude where you plan to ride. CAUTION: @ The drive chain gears and V-belt clutch should be adjusted when operating above a high altitude of 900 m (3,000 ft). Consult a Yamaha dealer. @ ESU00348 Adjusting the valve clearance The valve clearance changes with use, resulting in improper air-fuel mixture and/or engine noise. To prevent this from occurring, the valve clearance must be adjusted by a Yamaha dealer at the intervals specified in the periodic maintenance chart. 8-8

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8-8
ESU04860
Adjusting the high-altitude settings
Operating at high altitude reduces the performance of a
gasoline engine about 3% for every 305 m (1,000 ft) of
elevation. This is because there is less air as altitude
increases. Less air means less oxygen available for com-
bustion.
Your snowmobile can be adjusted to overcome most of
the problems found in high-altitude riding. Carburetor
adjustments are the most important. Less air at high alti-
tude makes the air/fuel ratio too rich, which can cause
poor performance. Common problems are hard starting,
bogging, and plug fouling. Proper carburetion adjust-
ments will correct the air/fuel ratio. Be sure to have a
Yamaha dealer make these adjustments.
Remember:
Less air at higher altitude means there is
less horsepower available, even with proper carburetion.
Expect acceleration and top speed to be reduced at
higher altitudes.
To overcome operating with less power at high altitudes,
your snowmobile may also require different settings for
the drive chain gears and V-belt clutch to avoid poor per-
formance and rapid wear. If you plan to operate your
snowmobile at an altitude different from the area where
you bought it, be sure to consult a Yamaha dealer. The
dealer can tell you if there are any changes necessary
for the altitude where you plan to ride.
CAUTION
:
@
The drive chain gears and V-belt clutch should be
adjusted when operating above a high altitude of
900 m (3,000 ft). Consult a Yamaha dealer.
@
ESU00348
Adjusting the valve clearance
The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To prevent
this from occurring, the valve clearance must be adjusted
by a Yamaha dealer at the intervals specified in the peri-
odic maintenance chart.
E_8gg.book
Page 8
Thursday, March 16, 2006
4:23 PM