Polaris Virage TX 2000 Service Manual page 163

ENGINE
Crankshaft Indexing
Crankshaft Indexing - Genesis FFI
Polaris Watercraft crankshafts are pressed together or
"indexed" so the connecting rod journal center lines are
120° apart from each other.
It is sometimes necessary to check multi-cylinder crank
shafts to verify that one cylinder has not been forced out
of position relative to the other cylinder or cylinders.
Causes for out-of-index crankshafts include but are not
not limited to:
• Hydrolock from water or fuel; See Troubleshoot
ing, Chapter 2.
• Impact to impeller from foreign object or acci
dent;
• Abrupt piston or other mechanical failure;
Following is a method of checking:
Rotate until
resistance
is felt
Degree
Wheel
II. 1
Bumper
Tool PN
2872604
Scribe
Mark
Disconnect battery ground cable and all spark plug high
tension leads; ground high tension leads to engine. Dis
connect lanyard from engine stop switch before proceed
ing with the following steps.
1 . Securely fasten a degree wheel on the flywheel or
output coupler/driveshaft. Use a large degree wheel
for more accuracy, and make sure it is mounted
concentrically with the crankshaft center line. Cut a
slot in a paper or cardboard degree wheel and slide it
over the driveshaft if engine and pump shaft is
installed in craft. Again, be sure to secure the degree
wheel.
2 . Sharpen a coat hanger or section of welding rod and
anchor it to a convenient spot. Point the sharpened
end at the outer perimeter of the flywheel or drive
coupler mounted degree wheel.
3 . Install bumper tool PN 2872604 into the magneto end
cylinder spark plug hole (front) (#1). (The ignition
timing is referenced by the magneto end.)
4 . Rotate the engine to bring the piston to the top of the
cylinder, making contact with the bumper tool. Scribe
a mark on the degree wheel. (See III. 1)
5 . Rotate the engine in the opposite direction until
similar contact is made with the bumper tool. Scribe
another mark on the flywheel. (See III. 2)
6 . Once both scribes are in place, remove bumper tool
and record the measurement between both scribes
and divide it in half. Make a scribe in the middle. This
is Top Dead Center.
7 . Bend the pointer or move the degree wheel until the
pointer aligns with the 120° mark on the degree
wheel.
Degree
Wheel
II. 3
Halfway be
tween scribes
is Top Dead
Center
3/00 4.52
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