WISECO piston kit for HONDA XR 250 L, XR 250 R from 1986 to 2004

WISECO offers this piston kit for HONDA XR 250 L, XR 250 R from 1986 to 2004. The piston slides in the cylinder and takes the force of the air-fuel combustion, passing it to the connecting rod and crankshaft.

Why choose a forged piston?

Instead of simply being cast, a forged piston is hot-pressed under very high pressure and then machined: its metal is denser and free of air pockets.

• Stronger when hot: it copes better with high revs, overheating and detonation.
• Lighter for the same strength: less stress on the connecting rod and bearings.
• Good to know: depending on the alloy, it expands a little more and is fitted with more clearance; slight noise when cold is normal.
• Why does it cost more? Forging tools, full machining and surface treatments cost more than simple casting.

Why choose WISECO?

Wiseco has forged its pistons in Mentor (Ohio, USA) since 1941 and controls the whole process, from aluminium bar to the friction-reducing ArmorGlide skirt coating. Its pistons are developed with Team Honda HRC in Supercross (450 class since 2018).

When should you replace the piston on your HONDA XR 250 R?

Harder starting, loss of power, blue smoke, oil consumption or a knock when cold: these are the signs of a tired top end.

No manufacturer hour figure for this model. Cross-Mania guideline: compression check every 50 h in hard use and every 100 h for leisure.

Specifications and fitting tips

• Contents: 1 x Piston, 1 x Ring Set #2973XC, 1 x Wrist Pin #S533, 1 x Circlip Set #CW17
• Displacement: 250 cm³
• Stroke: 59.50 mm
• Piston material: Forged 2618 aluminium
• Skirt coating: Uncoated
• Compression ratio: 10.5:1
• Dedicated forgings for an optimised strength-to-weight ratio

Available in several bores: standard size and oversizes for a rebored cylinder.

Cross-Mania tip: Measure the cylinder bore before ordering: the piston must match your cylinder size. Follow the manufacturer's break-in procedure and replace the top-end gaskets at the same time.

Also needed with this part

• Top-end gasket kit : PROX · PROX 250 L
• Spark plug : see the selection
• 4-stroke engine oil : MOTUL 10W50 · LIQUI MOLY 10W40 1 L
• Air filter : PROX 650 L

Compatibility

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

Fits:
HONDA XR 250 L 2004
HONDA XR 250 L 2003
HONDA XR 250 L 2002
HONDA XR 250 L 2001
HONDA XR 250 L 2000
HONDA XR 250 L 1999
HONDA XR 250 L 1998
HONDA XR 250 L 1997
HONDA XR 250 L 1996
HONDA XR 250 L 1995
HONDA XR 250 L 1994
HONDA XR 250 L 1993
HONDA XR 250 L 1992
HONDA XR 250 L 1991
HONDA XR 250 R 2004
HONDA XR 250 R 2003
HONDA XR 250 R 2002
HONDA XR 250 R 2001
HONDA XR 250 R 2000
HONDA XR 250 R 1999
HONDA XR 250 R 1998
HONDA XR 250 R 1997
HONDA XR 250 R 1996
HONDA XR 250 R 1995
HONDA XR 250 R 1994
HONDA XR 250 R 1993
HONDA XR 250 R 1992
HONDA XR 250 R 1991
HONDA XR 250 R 1990
HONDA XR 250 R 1989
HONDA XR 250 R 1988
HONDA XR 250 R 1987
HONDA XR 250 R 1986