SNOWMOBILE
12/18/07
S2007-011
2007 PZ50W/FXW/GTW/MW/VTW
Hard Starting in Extreme Cold Temperatures
PAGE 1 of 4
©2007 YAMAHA MOTOR CORPORATION, U.S.A.
Symptom:
Some affected units have experi-
enced hard starting in temperatures
below -15
º
F (-26
º
C).
Cause:
Reduced engine cranking speed in
extremely cold temperatures affects
the engine decompression and
ECU calibration. This can reduce
the engine starting performance.
Remedy:
Install ECU kit, which includes
a new ECU, two decompression
springs, and a cylinder head cover
gasket (see
Parts Information
sec-
tion for more details).
Additional
Notes:
It is normal for the engine to crank for several seconds before starting. However, early-season
extended-cranking time or engine not starting in temperatures above -15˚F (-26˚C) is usually
associated with the following:
• Stale gasoline (more than 30 days old) or summer-blend gasoline;
• Contaminated spark plugs caused by stale gasoline; or
• A weak or discharged battery caused by long cranking.
• It can also be caused by repeatedly starting and stopping the engine without allowing the
engine to reach operating temperature.
Should this be the problem, then perform the following:
1. Drain the fuel from the machine and replace it with fresh premium gasoline.
2. Replace the spark plugs.
3. Charge the battery properly using the correct charger.
4.
Do not start and stop the engine without allowing it to reach operating temperature.
Sold
Units:
Contact those customers who have reported hard starting in extreme cold temperatures and
arrange a convenient time to install the new exhaust decompression springs and ECU.
Unsold
Units:
N/A
Parts
Required:
Yes, Order one ECU kit per unit as required.
Warranty:
Submit a Service-Per-Bulletin (90 Code) Warranty Request for parts and labor. This 90-code
expires December 31, 2009.
