Engine / Cooling
3.55
Engi ne Inspec tion -- All Engines
Honing Procedure, Cont.
2. Place hone in cylinder and tighten stone adjusting knob until stone contacts the cylinder walls (DO NOT
OVERTIGHTEN). Cylinders may be wet or dry honed depending on the hone manufacturer’s
recommendations. Wet honing removes more material faster and leaves a more distinct pattern in the bore.
Using a 1/2I (13 mm) drill motor rotating at a speed of 300-500 RPM, run the hone in and out of the cylinder
rapidly until cutting tension decreases. Remember to keep the hone drive shaft centered to prevent edge
loading and always bring the stone approximately 1/2I (1.3 cm) beyond the bore at the end of each stroke.
Release the hone at regular intervals to inspect bore size and finish.
Port Chamfering
After honing the cylinders, chamfer all ports to remove sharp edges. To chamfer the ports, use a small hand grind-
er with a 1/2² -1² (12-25mm) diameter cylindrical grinding stone or sanding roll, a half round file, or a 3 sided
de-burring knife. Hold the cylinder securely by installing bolts in the exhaust mounting holes and clamping in a
soft jaw vise. The corners, top and bottom edges of ports should receive a standard chamfer (.3 -.6mm) with the
widest portion at the center of the port window. The sides of the ports require only de-burring (.05 - .3mm). Refer
to illustration below.
IMPORTANT: Cleaning the Cylinder After Honing
Scrub the cylinders thoroughly in hot, soapy water. Pay close attention to the area where the cylinder sleeve
meets the aluminum casting and use electrical contact cleaner if necessary to remove all traces of debris. Rinse
the cylinders in clear water and dry thoroughly with compressed air. Immediately apply Polaris Premium 2 Cycle
Lubricant or 2-stroke engine oil to all areas of the cylinder sleeve to prevent rust. Wipe cylinders with an oil coated
shop towel to clean all remaining honing material from the cross hatch of the cylinder bore, and re-oil.
Standar d Chamfer
(Typical)
Cylinder
CAUTION:
Do not exceed 20°
chamfer angle
Port
10-20°
.3-.6mm
(.012-.024²)
.05-.3mm
(.002-.012²)
Chamfer Angle
.3-.6mm
(.012-.024²)
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