Checking The Spark Plugs - Yamaha PZ50RTD Owner's Manual

Periodic maintenance and adjustment
1. Projection
2. Holder
1. Slot
1. Grommet
2. Close the shroud.
ECS00372
NOTICE
Make sure that all cables, hoses and
●
leads are routed properly before install-
ing the shroud and covers.
64
When installing the shroud and covers,
●
be sure to tighten the fasteners secure-
ly.
ESU11784

Checking the spark plugs

The spark plugs are important engine compo-
nents and are easy to inspect. The condition
of the spark plugs 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-
light tan color for a snowmobile that is being
ridden normally. If any spark plug shows a
distinctly 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 plugs because heat and deposits
will cause any spark plug to slowly break
down and erode. Consult a Yamaha dealer
before changing to a different type of spark
plug.
Specified spark plug:
Manufacturer:
NGK
Model:
CR9EKB
EWS00710
WARNING
Be sure to use the specified spark plug
and spark plug cap. Otherwise, the
T.O.R.S. may not work properly.
Spark plugs are produced in several different
thread lengths. The thread length or reach is
the distance from the spark plug gasket seat