WISECO Racer Elite Forged Piston for YAMAHA WRF 450, YZF 450 and FANTIC XEF 450, XXF 450 2020-2025

The WISECO Racer Elite WRE825M09700 forged piston (Ø 97 mm) is designed for YAMAHA WRF 450, YZF 450 and FANTIC XEF 450, XXF 450 from 2020 to 2025. A forged piston is made by squeezing a hot aluminium slug in a press, instead of pouring the metal into a mould. The metal is denser and stronger: the piston copes better with high revs and heat, which makes it the choice for racing engines.

Specifications

• Brand: WISECO
• Manufacturer part number: WRE825M09700
• Compression ratio: 14:1
• Piston diameter: 97 mm
• Engine: 4-stroke

When to replace it?

• Loss of power, sluggish pick-up, harder starting: compression is dropping.
• Piston slap on a cold engine, getting more and more noticeable.
• On teardown: vertical scoring on the skirt, stuck or worn rings, thick carbon on the crown.
• On a four-stroke: oil consumption, blue smoke and a fouled spark plug.

Replace the piston as set out in your bike's service manual, sooner if you race, and straight away as soon as these symptoms appear. As a Cross-Mania guideline, plan for a new piston every 30 to 60 hours of engine running depending on whether you race or ride for fun. Always measure the cylinder at the same time: a new piston in an oval cylinder won't last.

Fitting tips

1. Clean the cylinder and check it: diameter, ovality, taper and condition of the bore coating.
2. Check the end gap of each ring in the cylinder against the figures in the manual or the manufacturer's instructions.
3. Fit the rings with the mark facing up and the gaps staggered, never letting the ends of the oil control ring overlap.
4. Fit the piston with its arrow pointing to the exhaust side, oil the pin and the small end, then fit the circlips without distorting them, gap opposite the notch. A circlip that has been taken out is replaced with new piston pin circlips, never refitted.
5. Reassemble with a new top end gasket kit and tighten the cylinder head in a criss-cross pattern to the manufacturer's torque.
6. Refill the coolant, fit a new spark plug and change the oil with fresh engine oil and a new filter.
7. Break the engine in: warm it up gently, vary the revs and avoid sustained full throttle for the first hour.

Why WISECO?

Based in Mentor, Ohio, Wiseco designs, forges and machines its parts in the United States. Pistons, valves and clutch parts: the brand is known for forged parts built for hard-working engines.

Spare parts and items to plan

• Piston rings : VERTEX · ATHENA
• Piston pin : ATHENA
• Piston pin clips : WISECO
• Top-end gasket kit : see the selection
• Spark plug : NGK 4218 · NGK 96067
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• 4-stroke engine oil : MOTUL 10W50 · LIQUI MOLY 10W40 1 L

Frequently asked questions

Does the piston come complete?
Yes: piston, pin, circlips and ring(s). The top end gasket kit has to be ordered separately, because a head or base gasket can never be reused.

Can I replace just the rings later?
Yes, as long as the piston and cylinder are still within tolerance. Replacement rings can be ordered on their own, as can the piston pin and the circlips.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
FANTIC XEF 450 2025
FANTIC XEF 450 2024
FANTIC XEF 450 2023
FANTIC XEF 450 2022
FANTIC XXF 450 2022
YAMAHA WRF 450 2023
YAMAHA WRF 450 2022
YAMAHA WRF 450 2021
YAMAHA YZF 450 2023
YAMAHA YZF 450 2022
YAMAHA YZF 450 2021
YAMAHA YZF 450 2020