3 Namura Piston Kits fits Kawasaki Ultra 150 & 1200 STX-R .020 Over Bore 80.5mm

3 Namura Piston Kits for Kawasaki Ultra 150 & 1200 STX-R .020 Over Bore 80.5mm

This set of three Namura piston kits is a direct replacement for Kawasaki Ultra 150 and 1200 STX-R models, featuring a .020 over bore size of 80.5mm to restore lost compression and power after cylinder wear. These Namura piston kits for Kawasaki provide all necessary rings, pins, and circlips for a complete top-end rebuild on select Kawasaki watercraft.

Overview

These three Namura piston kits for Kawasaki Ultra 150 and 1200 STX-R are precision-engineered to .020 over bore (80.5mm), delivering a reliable solution for refreshing worn cylinders. Each kit includes high-quality rings, a wrist pin, and circlips, making it a complete set for restoring performance on Kawasaki personal watercraft engines. Designed for riders and mechanics rebuilding a 1200 STX-R or Ultra 150, these Namura piston kits offer a cost-effective path back to peak operation.

Built For Performance

• Forged aluminum construction provides high strength and heat resistance for sustained high-rpm use.
• Precision machined to 80.5mm diameter (.020 over bore) for proper cylinder clearance and compression restoration.
• Includes chrome-plated piston rings to reduce friction and improve ring seal during break-in.
• Complete kit with wrist pin and circlips simplifies installation and ensures proper component fitment.
• Namura's strict manufacturing tolerances help maintain consistent piston-to-wall clearance across all three kits.

Fits These Machines

• for Kawasaki Ultra 150
• for Kawasaki 1200 STX-R

On-The-Job Use

• Ideal for top-end engine rebuilds on high-mileage or performance-tuned Kawasaki watercraft.
• Suitable for marine racing or recreational riding where engine reliability at wide-open throttle is critical.
• Commonly used in DIY garage rebuilds or professional marine shops performing cylinder boring and piston replacement.
• Effective for restoring lost power on engines that have experienced scuffing, scoring, or ring wear from age or lack of maintenance.

Specs At A Glance

Good To Know

Q: Do I need to hone or bore the cylinders before installing these pistons? A: Yes, because these are .020 over bore pistons for Kawasaki, the cylinders must be professionally bored and honed to the correct clearance for the 80.5mm piston diameter to ensure proper ring seating and oil control.

Q: Will these pistons work in any other Kawasaki model besides the Ultra 150 and 1200 STX-R? A: These pistons are specifically designed for the Kawasaki Ultra 150 and 1200 STX-R engines; confirm your cylinder bore and serial number before ordering to avoid fitment issues with other models.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.