Tool Kit; Checking The Spark Plug - Yamaha VK540V Owner's Manual

ESU01430

Tool kit

1
The owner's tool kit has the tools which are sufficient for
most periodic maintenance and minor repair. A torque
wrench is also necessary to properly tighten nuts and
bolts.
846-013
1 Tool kit
NOTICE
@
Before starting the engine, make sure that the tool
kit is firmly seated in the holder and is secured with
the holding band.
@
TIP
@
If you do not have a torque wrench available during a
service operation requiring one, take your snowmobile to
a Yamaha dealer to check the torque settings and adjust
them if necessary.
@
ESU01443*

Checking the spark plug

The spark plug is an important engine component and is
easy to inspect. The condition of the spark plug can indi-
cate the condition of the engine. Check the coloration on
the white porcelain insulator around the center electrode.
The ideal coloration at this point is a medium to a light
tan color for a snowmobile that is being ridden normally.
If a spark plug shows a distinctly different color, there
could be something wrong with the engine. For example,
a very white center electrode porcelain color could indi-
cate an intake track air leak or carburetion problem for
that cylinder. Do not attempt to diagnose such problems
yourself. Instead, take the snowmobile to a Yamaha
dealer for inspection and possible repairs. You should
periodically remove and inspect the spark plug because
heat and deposits will cause a spark plug to slowly break
down and erode. Consult a Yamaha dealer before chang-
ing to a different type of spark plug.
Specified spark plug:
BR9ES (NGK)
8-4