Polaris FST IQ 2007, Руководство по обслуживанию

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5.6
Engine and Cooling Systems
Piston Inspection
Check piston for scoring or cracks in piston crown or pin
area. Excessive carbon buildup below the ring lands is an
indication of piston, ring or cylinder wear. On Fuji engines,
measure piston outside diameter at a point that is 1/2
"
(12.7mm) up form the bottom of the skirt at a 90
°
angle to
the direction of the piston pin.
Subtract this measurement from the minimum cylinder
measurement (90
°
to the pin). If clearance exceeds the
service limit, the cylinder should be re-bored (replaced if
Nicasil-lined) and new pistons and rings installed.
Piston Ring Installed Gap
Position the ring 1/2
"
(1.3 cm) from the top of the cylinder
using the piston to push it squarely into place. Measure
installed gap with a feeler gauge at both the top and
bottom of the cylinder.
NOTE: A difference in end gap indicates cylinder
taper. The cylinder should be measured for
excessive taper and out-of-round. Replace rings if
the installed end gap exceeds the service limit.
Always check piston ring installed gap after re-
boring a cylinder or when installing new rings.
Piston rings are installed with marking or beveled side up.
Reed Valve Inspection
1. Loosen he hose clamps
2. Remove the carburetor or the throttle body from the intake
boots.
3. Remove the intake boot fasteners and hose holders (if
applicable).
4. Remove the intake assembly.
5. Separate the intake boot(s) from the reed cage.
6. Separate the reed stuffer(s) from the reed cage and inspect
the reeds before they are removed from the reed cage.
NOTE: Measure the air gap between the fiber reed and
the reed block. The air gap should not exceed .015"
(.38mm). If clearance is excessive DO NOT attempt to
reverse the reeds to reduce the air gap. Always replace
them if damaged or worn. Check each fiber reed for white
stress marks or missing material.
7. If damaged remove and replace the reeds on the reed cage.
Bearing Fit
Any time crankshaft bearing failure occurs and the case is
reused, check the bearing fit into the case halves using the
following procedure.
With case halves cleaned, reinstall the main bearings with
a piece of Plastigage between the bearing race and
crankcase.
Install and torque the crankcase fasteners to specifica-
tion. Take the crankcase apart, and then measure the
Plastigage. Compare Plastigage width to interference fit
The air gap should not exceed .015” (.30mm)