1989 1990 1991 YAMAHA MOTO-4 250 MOTO4 YFM250 PISTON CYLINDER TOP END REBUILD KIT ATV QUAD

NEW STOCK BORE CYLINDER KIT

REBUILD YOUR MACHINE WITH OUR NEW HIGH QUALITY OEM REPLACMENT CYLINDER KIT AND GET YOUR MACHINE UP AND RUNNING AGAIN!

Maximize Power, Minimize Cost: The Ultimate Top-End Rebuild Solution

Are you staring down a top-end rebuild and dreading the dealership price tag for a brand-new factory cylinder? You don't have to drain your wallet to get your machine running like new again.

By upgrading to a machined steel sleeve cylinder block paired with a premium name-brand piston, you can completely restore your engine's power and reliability for a fraction of the OEM cost & saving yourself time.

Here is why engine builders and weekend warriors alike are making the switch:

• Uncompromised OEM Performance: You don't have to sacrifice speed or torque to save money. High-quality steel sleeves are machined to exact factory specifications, ensuring perfect piston-to-cylinder clearance, optimal compression, and the crisp throttle response you expect.

• Massive Cost Savings: Factory-plated cylinders come with premium markups. Choosing a sleeved cylinder keeps hundreds of dollars in your pocket—giving you extra budget for upgrades, gear, or your next racing fee.

• Future-Proof Durability: Unlike standard OEM Nikasil-plated cylinders that must be completely stripped and replated if damaged, a steel sleeve can simply be bored and honed to the next oversize. This makes future rebuilds significantly cheaper and faster.

• Race-Proven Reliability: We pair our steel sleeves with trusted, name-brand aftermarket pistons (like Wiseco, ProX, or Vertex). These pistons are engineered from high-strength aerospace alloys, offering durability that often exceeds stock components under extreme riding conditions.

Don't pay more for the same ride. Get the perfect balance of elite performance, rugged longevity, and unbeatable value. Rebuild smart, ride hard, and leave the inflated OEM prices in the dust.

KIT INCLUDES:

AFTERMARKET CYLINDER BLOCK

(CYLINDER BLOCK HAS A GEOMETRY, CIRCULARITY SHEET INCLUDED)

NAMURA NA-40015 PISTON KIT

NAMURA NA-40015T TOP END GASKET KIT

NGK D8EA SPARK PLUG

AFTERMARKET AIR FILTER

HIFLO HF143 OIL FILTER

 

FITS:

1989 - 1991 YAMAHA MOTO-4 250