WR250X: Engine

• Kit includes aluminum cylinder with nickel-carbide coating designed with larger water jackets
• Specially designed, high performance, hard anodized power valves (cannot use OEM)
• Forged piston with molybdenum coating
• Does not include cylinder head.

You will need to tune your EFI with something like the Power Commander V to get the most out of your Big Bore kit.

This is a completely rebuildable stroker crank (3mm additional stroke) turns your mild mannered 250cc motor into a 263cc trail shredding monster! OK, maybe not, but sure makes it a fun machine.

Want the COMPLETE package? Order a Big-Bore kit to go with your stroker! That will give you a 308cc ripper! That is 24% larger than the stock 250. This package includes the Athena Big Bore Kit plus the 3mm Hot Rods Stroker Crank with new Genuine Yamaha crank bearings.

You will need to tune your EFI with something like the Power Commander V to get the most out of your Stroker kit.

For stock bore Hot Rods highly recommends you use the Vertex Stroker Piston Kit.

If you're plannig to or already have a stroker crank setup in your Yamaha WR250R/X, you'll need this stroker piston.

Features:

• All piston skirts are coated with a hi-tech Molybdenum Disulphite coating for faster break-in time and increased piston life
• Cast Replica piston kits are gravity cast aluminum alloy (not forged) with 18% silicone content, which produces an extremely light but very strong piston
• Forged Replica pistons are forged from 2618 aluminum for superior strength and durability
• Forged High Compression pistons improve power and torque across entire rpm range
• Forged Big Bore pistons increase engine’s displacement, torque, and peak horsepower
• Forged Replica pistons are forged OE replacements
• All pistons are heat treated with a T-5 hardening and tempering cycle
• Replica pistons and all rings are OEM replacements
• Kits include piston, rings, wrist pin and circlips
• Two stroke replacement rings are sold individually (Example if your piston has two rings you will want to order two rings)
• Four-stroke piston rings sold as a set

7.48mm diameter - Includes three valve shims of each size from 1.20 to 3.50mm in .05mm increments.

141 shims in total. 0.57 cents per shim! Does your local dealer have the shims you need?

K&L® shims exceed the maximum of the Apparent Rockwell Hardness "C" scale. Shims average 47.0 compared to the 46.0 maximum.

This kit fits KLR650 87-18 as well as other brands and models , please verify correct size for your model before purchase.

K&L® shims exceed the maximum of the Apparent Rockwell Hardness "C" scale. Shims average 47.0 compared to the 46.0 maximum.

These kits fit multiple brands and models, please verify correct size for your model before purchase.

Higher pressure in the cooling system, raises the coolant boiling point and increases protection from coolant loss due to overheating.

23 PSI - 1.6 Bar.

DRC is one of the leading manufacturers of silicone hose kits for motorcycles.

• Durable silicone radiator hose for dirt bikes
• Available for MX, ED racers and street dirt bikes
• Smooth inner diameter allows for increased coolant flow
• Printed white DRC logo. Available in red or blue colors

Keep yourself COOL with a set of Moto Hoses. Moto Hoses are what you need to handle the heat that your bike is putting out whether you're pushing it to the limit or just stuck in slow city traffic.

Each Kit Contains:

• Color matched carb vent hoses
• Color matched fuel line
• Color matched coolant overflow hose
• Moto Hose is used by Rock River Yamaha and Honda of Troy motocross teams
• Moto Hose for the WR250R/X is available in Blue or White

From Barnett, the number one name in motorcycle clutches since 1948, we now offer a complete high performance clutch set. This includes Kevlar friction plates, steel drive plates and stronger springs.

The Dirt Racer Complete Clutch Rebuild Kit is the ultimate package for your Yamaha, here's why:

'Stack Height' is the all important factor when renewing a clutch and riders are always best to buy a complete kit instead of separate single plates as sold by manufacturers. Replacing just the worn plate (or plates) may not even get close to rebuilding your clutch to its original stack height and all you get is clutch slip and the job has to be done again.

• Complete set of stack height controlled anti-swell friction plates
• The friction plates are forged allow with wide "Ear" construction to spread the load in the clutch basket and prevent "Dogging" (when the ears cut into the allow clutch basket) which causes a rough clutch, promotes slippage plus it ruins an expensive part of your engine
• EBC unique alloy article impregnated clutch facings that wear longer and resist burning
• 15% stronger heavy duty, shot peened clutch springs to clamp those plates together firm and strong for the life of your clutch

Hinson Clutch Plates available as a set of just Fiber Plates or just Steel Plates or as a complete set including both.

Hinson Clutch Components sells the best clutch components available in the world. Hinson equipped machines have won 224 National and World Championships in our 20 years of business.

• Optimum hook up with minimum heat build up provides high performance
• Developed with and recommended to enhance the performance of Hinson clutch baskets, inner hubs, and pressure plates
• Exceptional production tolerances and flatness
• All fiber plates use organic non-abrasive materials to avoid damage to rest of motor as plate materials break down and are circulated through engine by oil
• Can be used with OEM baskets, inner hubs, and pressure plate

Choose standard bore top end, big bore top end or a complete gasket set for the standard bore motor. These are high-quality gasket sets from Athena.

• The Complete Gasket set for the stock bore does NOT include Oil Seals. Must purchase those separately.
• The Top End Gasket set for the stock bore includes all the necessary gaskets, rubber parts and valve stem seals for a complete top end rebuild.
• The Big Bore Top End set includes a base and head gasket

If you need a new clutch, you probably need a new gasket to seal that cover when you are all done. Genuine Yamaha part.

This kit includes the large O-Ring that goes on the end of the filter and the small O-Ring that seals the hole just above that. Both are factory Yamaha parts.

Providing unbeatable performance and exceptional value, Hiflo filtro is the best-selling brand of aftermarket filters for motorcycles, scooters, and ATVs worldwide. The filters are also supplied to original equipment manufacturers as well as private label brands.

You pay $3.90 per filter with our value 10-pack!

• Bolts are CNC-machined from high-quality aluminum
• Embedded magnet helps keep bolt in place
• Pre-drilled holes make for easy installation of safety wires

A 10-pack of drain plug sealing crush washers. Replace your sealing washer at every oil change to prevent a leak.

Extra protection for your motor! Strong magnet at the end of the plug picks up metallic flakes in your oil, protecting your engine!

Hardened chrome vanadium steel with built in rubber insert to hold spark plug steady.

Thin wall bi-hex sockets designed to access narrow spark plug holes.

Fits 3/8" square drive and hex drive, 14mm, 16mm, 18mm, 21mm.

Keep your motor running right with a fresh plug.

A Dual Electrode spark plug will last longer than a single electrode plug because the wear is shared between the electrodes.

E3 Resistor Spark Plugs

• Unique electrode shape maximizes the power created by the spark plug – Diamond Fire technology
• Electrode is a combination of performance and technology that results in an improved flame kernel shape
• This flame front ignites the bulk air/fuel mixture faster, moves heat into the combustion chamber faster and creates a more localized pressure front for faster pressure rise during the cylinder power stroke
• The result is more complete combustion and an improvement in engine performance
• A truly premium performance plug
• Sold individually, unless otherwise stated.

Iridium spark plugs are made with premium quality materials.

Iridium plugs last longer than standard ones, meaning you won't have to replace them as often.

• The ultimate in the evolution of spark plug technology and performance from an industry leader
• The iridium electrode is 25% smaller than a platinum electrode, and it's just 1/4 the size of a conventional nickel electrode
• Ultra-small diameter center electrode reduces voltage requirement and extends ignition system life
• Metal shell plating has enhanced anti corrosion qualities

Sold individually, unless otherwise stated.

The genuine factory shop service and repair manual. This is the reference manual Yamaha dealers use in their service departments. It has all the necessary info to do any maintenance or repairs to your WR250R or X.

• Contains degree wheel, standard unit indicator, adjustable magnetic stand, and three positive stops (10 mm, 12 mm and 14 mm threads)
• Can be used to install and adjust timing of any cam
• Wooden carrying case

Made from medium carbon steel with hardened jaws. It features spanner pins and the jaws open up to 5" wide. It's ideal for holding clutch hubs, flywheels, gears, sprockets, etc. Made by Motion Pro.

This tool is designed to separate vertically split crank case halves on two and four stroke engines. Adjustable arms allow it to be used on multiple bolt patterns found on a variety of makes and models of motorcycles. Industrial grade steel construction with black oxide finish for long service life. Comes with 8mm mounting bolts and 6mm adapters. Protective carrying case included.

Works Connection Billet Plugs for your left side case. These blue plugs includes both the timing mark plug and the crankshaft access plug.

Unless you have managed to bash yours on a rock, this is an item of pure bling, but hey, there is nothing wrong with that! This CNC Oil Filter Cover is made from A7009-T6 aluminum with the 'Zeta' logo machined into the front and anodized in blue to really stand out on your Yamaha. It's also lighter than stock.

For easy removal of recessed oil filters.

Conical point screws pierces and grabs the metal end cap of the filter.

reduces potential damage to the engine cases.

NOT for use on re-usable oil filters.

A 3-pack of easy to apply strips measure the temperature of engine, suspension, and radiator components. Temperature range 146° to 248°

Thread Chasers are designed to clean and re-cut damaged aluminum threads.

This kit contains the two sizes most common on metric motorcycles, M6x1.0 and M8x1.25.

Thread Chasers also remove dirt and metal shavings that become captured in thread grooves.

Uses 8mm or 10mm hex sockets, a Must for all tool kits.

• 26 straight blades
• SAE and metric markings
• Check for clearance on valves, ignition points etc.
• Includes 26 blades varying in thickness from .0015"/.038 mm to .025"/.635 mm