BOYESEN Reed Petals for OEM reed valve for YAMAHA YZ 85 2002-2026

The BOYESEN BOY6105 set of reed petals is designed for YAMAHA YZ 85 from 2002 to 2026. In a two-stroke, the petals of the reed valve block open to let the mixture into the crankcase, then close to stop it coming back out. Tired or chipped petals don't close properly: the engine loses bottom end and sharpness.

Key features

• Designed to fit the stock reed block.
• Designed for Boyesen reed blocks.
• Made in the USA.

Specifications

• Brand: BOYESEN
• Manufacturer part number: BOY6105
• EAN code: 804429008452
• Weight: 300 g
• Engine: 2-stroke

When to replace it?

• Petal tips chipped, split or frayed.
• Petals no longer sitting flat on the cage (visible gap).
• Weak pick-up at low revs, hard starting.

Inspect the petals at least once a season and at every piston change; replace them as soon as a tip is damaged.

Fitting tips

1. Remove the reed valve block and clean the cage.
2. Fit the petals the right way round and tighten the petal screws with threadlocker to the recommended torque.
3. Check that the petals sit flat on the cage before refitting.
4. Refit with a new reed block gasket.

Why BOYESEN?

Boyesen is an American brand specialising in the intake and the engine covers of two-stroke engines: reed petals, RAD Valve reed blocks, engine covers and Supercooler water pumps.

Spare parts and items to plan

• Reed block gasket : BOYESEN · V FORCE
• Spark plug : NGK 6801 · NGK 3830
• Carburettor repair kit : PROX · ALL BALLS

Frequently asked questions

Do I need to re-jet?
Usually not on a well-tuned engine; check the colour of the spark plug after the first few rides.

Compatibility

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

Fits:
YAMAHA YZ 85 2026
YAMAHA YZ 85 2025
YAMAHA YZ 85 2024
YAMAHA YZ 85 2023
YAMAHA YZ 85 2022
YAMAHA YZ 85 2021
YAMAHA YZ 85 2020
YAMAHA YZ 85 2019
YAMAHA YZ 85 2018
YAMAHA YZ 85 2017
YAMAHA YZ 85 2016
YAMAHA YZ 85 2015
YAMAHA YZ 85 2014
YAMAHA YZ 85 2013
YAMAHA YZ 85 2012
YAMAHA YZ 85 2011
YAMAHA YZ 85 2010
YAMAHA YZ 85 2009
YAMAHA YZ 85 2008
YAMAHA YZ 85 2007
YAMAHA YZ 85 2006
YAMAHA YZ 85 2005
YAMAHA YZ 85 2004
YAMAHA YZ 85 2003
YAMAHA YZ 85 2002