Engine / Cooling
3.59
Crankshaft Indexing - DIt Engines
NOTE: Domestic T win Timing Marks: 180°
Domestic Triple Timing Marks: 120°
Polaris DIt engines have a fuel injector mounted in place
of the standard spark plug hole. The spark plugs on DIt
engines are mounted on the side of the cylinder heads.
Because of this arrangement, the use of a bumper tool,
PN 2872604, is required to establish the degree wheel
timing marks.
CAUTION:
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 Ill. 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 Ill. 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 either the 180° or 120° mark on
the degree wheel.
8. Verify the mark be performing steps 4 and 5 again.
9. Install bumper tool into either the PTO or CTR
cylinder depending on engine model. Repeat steps 4
through 6. Proceed with performing steps 4 through 6 on the PTO cylinder (1200s only). The distance
between marks must be either 180°± 2° (Twins) or 120°±2°(Triples).
Degree
Wheel
Piston
Rotate until
resistance
is felt
Scribe
Mark
Ill. 1
Bumper
Tool PN
2872604
Degree
Wheel
Piston
Bumper
Tool PN
2872604
Rotate until
resistance
is felt
Scribe
2nd Mark
Ill. 2
Degree
Wheel
Piston
Halfway be-
tween scribes
is Top Dead
Center
Ill. 3
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