40033M07800 Wiseco Std Piston Kit for Yamaha YZF-R1 2009-2013 78mm 13.5:1

Wiseco Std Piston Kit for Yamaha YZF-R1

This Wiseco Std Piston Kit for Yamaha YZF-R1 is a 78.00 mm bore, 13.5:1 compression piston assembly that restores factory top-end geometry on 2009-2013 models; cross-reference OEM 40033M07800.

Overview

This Wiseco Std Piston Kit for Yamaha YZF-R1 delivers a direct-fit 78.00 mm bore and 13.5:1 compression ratio for 2009-2013 machines. It suits track riders and street owners rebuilding a worn top end or chasing consistent compression. The kit pairs an OEM cross-reference 40033M07800 with the piston, rings, pin, and clips needed to complete the job.

Built For Performance

• 78.00 mm standard bore diameter with 13.5:1 compression ratio
• Forged piston construction for strength at high rpm
• OEM cross-reference 40033M07800 for easy parts matching
• Ring set, wrist pin, and circlips included for a complete top-end refresh
• Designed for 2009-2013 Yamaha YZF-R1 fitment
• Precision-machined skirt and crown geometry for consistent sealing

Fits These Machines

• for Yamaha YZF-R1 2009
• for Yamaha YZF-R1 2010
• for Yamaha YZF-R1 2011
• for Yamaha YZF-R1 2012
• for Yamaha YZF-R1 2013

On-The-Job Use

• Track day engine refreshes after ring wear or compression loss
• Top-end rebuilds on high-mileage street machines
• Preventive maintenance during engine teardown
• Performance builds needing a standard bore high-compression piston

Specs At A Glance

Good To Know

Q: Do I need to hone the cylinder before installing this piston? A: Yes, most rebuilds call for a fresh hone or bore check to ensure the new rings seat properly against the cylinder wall. Confirm your existing bore is at the standard 78.00 mm size before ordering.

Q: Are ring end gaps pre-set out of the box? A: No, ring end gaps should always be checked and filed to the spec listed in your service manual during assembly. Skipping this step can cause ring binding or poor compression.

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