- Big Bore Kit
- Brand
- 50 Caliber Racing (53)
- Advantage Parts (28)
- Alpha Rider (36)
- Athena (163)
- Athena Az Quad Parts (30)
- Bbr Motorsports (79)
- Cylinder Works (139)
- Harley-davidson (30)
- Honda (55)
- Hyway (31)
- Niche (68)
- Power Part Pros (57)
- S & S Cycle (167)
- Smm (29)
- Tb Parts (173)
- Tbparts (74)
- V-twin (37)
- Vertex (51)
- Wiseco (95)
- Yamaha (60)
- Other (2757)
- Compatible Make
- Engine Type
- Machine Type
- Material
- Type
- Big Bore (43)
- Big Bore Kit (178)
- Big Bore Top End Kit (6)
- Block Cylinder (6)
- Complete Cylinder (33)
- Cylinder (22)
- Cylinder Barrel (67)
- Cylinder Block (11)
- Cylinder Kit (85)
- Cylinder Piston Kit (8)
- Cylinder Rebuild Kit (6)
- Engine (5)
- Engine Kit (6)
- Engine Rebuild Kit (206)
- Piston (14)
- Piston Kit (108)
- Rebuild Engine Kit (6)
- Top End Kit (11)
- Top End Rebuild (5)
- Top End Rebuild Kit (45)
- Other (3341)
For Polaris 325 78mm Big Bore Cylinder Piston Gasket Kit Top End
The OEM standard bore for this engine is 77.95mm. This 78mm cylinder kit is a Big Bore Performance Upgrade that increases displacement. Precise dimensions: piston diameter 78.0mm (approximate OS spec), piston rings 78mm set (2 compression rings +1 oil ring). The kit includes a 78mm cylinder block (cast aluminum alloy), 78mm piston, piston rings, wrist pin, circlips, and a full top-end gasket set (cylinder head gasket, base gasket, valve seals). Professional installation is recommended for a complete top-end rebuild.
Ideal for restoring lost compression, eliminating blow-by, and refreshing top-end performance on Polaris 325cc utility ATVs. Perfect for farm work, trail riding, and engine rebuilding. Note: Please measure your original cylinder bore before ordering. Oversize piston options available for worn cylinders: +0.50mm (78.45mm).
And +1.00mm (78.95mm).