Restore reliable top-end performance with the NAMURA NX-30000-4K Top End Kit for select 1989–2000 Suzuki RM125 models. Designed for cylinders using a 55 mm +1.00 piston size, this complete kit includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit needed for a comprehensive upper-engine rebuild. The kit is intended for fitment on 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, and 2000 Suzuki RM125 motorcycles.
The NAMURA piston uses a hypereutectic casting process that increases silicon content to help control expansion, improve wear resistance, and support operation at elevated cylinder temperatures. Its MOS2, or Teflon/molybdenum, coated skirts use a rolled-on application process designed to create a stronger bond than conventional spray-on coatings. This coating helps reduce friction, improve heat transfer, and minimize the risk of cold seizures during engine operation.
Additional piston enhancements include machined smooth heads to help reflect combustion heat and reduce carbon buildup, along with anodized domes that improve heat resistance and durability. These design features help protect the piston crown and support consistent performance in demanding motocross applications. Verify the cylinder condition, required oversize, and exact motorcycle year before installation to ensure proper fitment. This NAMURA manufacturer part number is NX-30000-4K, and the corresponding vendor part number is 185-30004.
Features:
- Complete top-end kit with piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 55 mm +1.00 piston size for compatible Suzuki RM125 applications
- MOS2 Teflon/molybdenum coated skirt helps reduce friction, improve heat transfer, and minimize cold-seizure risk
- Machined smooth piston head helps reflect combustion heat and reduce carbon buildup
- Anodized piston dome improves heat resistance and durability
- Hypereutectic casting process provides controlled expansion and increased wear resistance
- Fits select 1989–2000 Suzuki RM125 models
- Brand: NAMURA
- Manufacturer part number: NX-30000-4K
- Vendor part number: 185-30004
Fitment:
1989 Suzuki RM125
1990 Suzuki RM125
1991 Suzuki RM125
1992 Suzuki RM125
1993 Suzuki RM125
1994 Suzuki RM125
1995 Suzuki RM125
1996 Suzuki RM125
1997 Suzuki RM125
1998 Suzuki RM125
1999 Suzuki RM125
2000 Suzuki RM125