- Big Bore Kit
- Brand
- 50 Caliber Racing (37)
- Advantage Parts (27)
- Alpha Rider (32)
- Athena (77)
- Athena Az Quad Parts (21)
- Bbr Motorsports (53)
- Cylinder Works (70)
- Honda (24)
- Hyway (27)
- Niche (47)
- Polaris (21)
- Power Part Pros (57)
- S & S Cycle (97)
- Smm (26)
- Tb Parts (127)
- Tbparts (41)
- V-twin (34)
- Vertex (45)
- Wiseco (60)
- Yamaha (37)
- Other (1771)
- Engine Type
- Machine Type
- Make
- Type
- Big Bore (17)
- Big Bore Kit (95)
- Complete Cylinder (7)
- Cruiser (4)
- Cylinder (18)
- Cylinder Barrel (21)
- Cylinder Head (4)
- Cylinder Kit (47)
- Cylinder Piston Kit (4)
- Cylinder Rebuild Kit (6)
- Engine Kit (5)
- Engine Parts (5)
- Engine Rebuild Kit (37)
- For Linhai Lh300 (5)
- Piston (10)
- Piston Kit (56)
- Supercharger Kit (3)
- Top End Kit (4)
- Top End Rebuild (4)
- Top End Rebuild Kit (20)
- Other (2359)
- Year
Koso North America 4-Valve Head with 170cc Big Bore Kit HONDA Grom & Z125 Monkey
170cc BIG BORE & 4V HEAD KIT GROM/MONKEY 13-21. Ideal engine part to complete Koso's big bore kit. Unique four-valve design increases air flow and performance. Provides more power and torque.
Features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves.