Periodic maintenance and adjustment
52
To install an upper cover
1.
Insert the projections on the upper cover
into the slots, fit the holders on the cover
onto the grommets, and then tighten the
fasteners.
2.
Close the shroud.
NOTICE
ECS00371
●
Make sure that all cables, leads, etc., are
routed properly before installing the
shroud and covers.
●
When installing the shroud and covers,
be sure to tighten the fasteners secure-
ly.
ESU11782
Checking the spark plugs
The spark plug is an important engine compo-
nent and is easy to inspect. The condition of
the spark plug can indicate 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 dis-
tinctly different color, there could be some-
thing wrong with the engine. For example, a
very white center electrode porcelain color
could indicate an intake track air leak or car-
buretion problem for that cylinder. Do not at-
tempt 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
changing to a different type of spark plug.
1. Projection
2. Holder
1. Grommet
1. Slot
Specified spark plug:
Manufacturer:
NGK
Model:
CR9EKB
U8GK12E0.book Page 52 Monday, May 19, 2008 11:17 AM
