BOYESEN Pro Series Reed Petals for OEM reed valve for YAMAHA WR 250, YZ 250 1990-1997

The BOYESEN Pro Series BOYPRO-09 set of reed petals is designed for YAMAHA WR 250, YZ 250 from 1990 to 1997. 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

• Carbon-fibre top petal and fibreglass/epoxy bottom petal: dual-stage operation.
• Designed to fit the stock reed block.
• Designed for Boyesen reed blocks.
• Made in the USA.

Specifications

• Brand: BOYESEN
• Manufacturer part number: BOYPRO-09
• EAN code: 804429005512
• 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 · ATHENA
• Spark plug : NGK 3430 · NGK 3521
• 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 WR 250 1997
YAMAHA WR 250 1996
YAMAHA WR 250 1995
YAMAHA WR 250 1994
YAMAHA WR 250 1993
YAMAHA WR 250 1992
YAMAHA WR 250 1991
YAMAHA WR 250 1990
YAMAHA YZ 250 1996
YAMAHA YZ 250 1995
YAMAHA YZ 250 1994
YAMAHA YZ 250 1993
YAMAHA YZ 250 1992
YAMAHA YZ 250 1991
YAMAHA YZ 250 1990