Top-End Kit for Sea-Doo 947, 951; Kawasaki 440, 550; Yamaha 500, 650; Polaris 65

1998 GSX Limited (White Motor)

Piston to Cylinder Clearance:
The piston size plus the clearance equals the final bore size. For the recommended clearances by make and model, see Table 1. The cylinder first should be bored to within 0.002 of the final bore size. The remaining 0.002 should be removed with a 400 grit cylinder hone. The honing process should be controlled such as to leave a 45 degree crosshatch pattern on the cylinder wall.

Port Chamfering:
Once the cylinder is honed to the final size, all of the ports in the cylinder wall should be chamfered with a file or chamfer tool. The chamfered edge should be cut at approximately a 30 degree angle around the entire port. The cylinder should then be honed with a 400 grit flex hone to apply a uniform finish and to re-establish the 45 degree cross-hatch pattern.

Cylinder Cleaning Process:
Clean cylinders in warm soapy water using a firm plastic brush (such as a tooth brush), then dry, and immediately lubricate with 2-stroke oil. Honing grit tends to reside in the crosshatch and must be scrubbed out. An extremely clean cylinder free of grit is critical in order to avoid drag marks and other damage to the cylinder wall after assembly.

Setting the Ring Cap:
Place the piston ring in the cylinder. Use the piston to push the ring approximately 5mm from the top of the cylinder in order to square the ring in the cylinder. Use a feeler gauge to measure the gap between the ends of the ring. If the gap is too small, one end of the ring must be filed. Re-install the ring and measure again to confirm the final dimension. Recommended ring gap clearances are shown in Table 2.


Piston Installation:
Install the base gasket (we recommend Threebond 1211 as a gasket treatment). Lubricate the wrist pin bearing with 2-stroke oil and install the piston on the connecting rod. The designation mark on the piston crown points in the direction as shown in Table 3. Install the c-clips with the open end in either the 6 or 12 oclock position. Install the rings onto the piston. Using your hands or a ring compressor, collapse the rings into the ring grooves and install the cylinder. Torque cylinder to proper torque specifications.

Table 1: Piston to Cylinder Clearance
Clearance	Application
2 Stroke
.004-.005	Kawasaki 440, 550, 650, 750, 900, 1100 Yamaha 500, 650, 701, 760, 1100, 1200
.0045-.0055	Yamaha 800, 1200pv, 1300
.005-.006	Seadoo 580, 650, 720, 800 Polaris 650, 750, 780, 900 Kawasaki 1200
.007-.008	Polaris 700, 1050 Seadoo 951, 800 RFI
4 Strokes
.001-.0022	Seadoo 112 (N/A)
.002-.004	Seadoo 113 (S/C)
.002-.003	Yamaha 408, 410, 411
.0015-.0025	Kawasaki 213, 214
.0005-.0015	Honda 600, 601

Table 2: Ring End Gap
Clearance/Tolerance	Application
2 Strokes
.011 +/- .003	Kawasaki 1100
.012 +/- .002	Seadoo 800
.012+/- .004	Kawasaki 440, 550, 650 Yamaha 500, 650, 701, 760, 1100, 1200, 800,1200pv Tigershark 640, 770, 1000
.013 +/- .003	Seadoo 580, 650, 720 Kawasaki 750, 900, 1200
.013 +/- .005	Polaris 650, 700, 750, 780
.014 +/- .004	Polaris 900, 1050
.019 +/- .001	Tigershark 900
.022 +/- .003	Seadoo 951/DI
4 Strokes
.015-.021	Yamaha FX Top Ring
.019-.027	Yamaha FX Middle Ring
.011-.023	Yamaha FX Oil Ring
.013-.017	Yamaha VX/FXHO Top Ring
.017-.023	Yamaha VX/FXHO Middle Ring
.004-.014	Yamaha VX/FXHO Oil Ring
.006-.014	Seadoo Top Ring/Middle Ring
.006-.012	Seadoo Oil Ring
.010-.016	Kawasaki Top Ring
.016-.022	Kawasaki Middle Ring
.016-.023	Kawasaki Oil Ring
.007-.013	Honda Top Ring
.016-.022	Honda Middle Ring
.010-.030	Honda Oil Ring

Table 3: Piston Arrow Direction
Make	Engine	Marking	Position
Seadoo	All	Arrow	Towards exhaust
Kawasaki	All (except 4-stroke)	Arrow	Towards Exhaust
Kawasaki	4-strokes	Dot	Towards exhaust
Polaris	650, 750, 780	Arrow	Towards front
Polaris	700, 900, 1050	Arrow	Towards exhaust
Yamaha	500	UP	Towards front
Yamaha	All others	Arrow	Towards exhaust
Tigershark	640, 1000	Arrow	Towards exhaust
Tigershark	770, 900	Dot	Towards exhaust
Honda	4-strokes	In	On the intake side