BORE KIT 415cc

87mm forged piston, 10.8:1 compression

A great option for fast-revving power. Better throttle response, more torque and horsepower

INCLUDES: Piston, pin, rings, circlips, headgasket, basegasket

REQUIRES: Boring, rejetting.

#00308

$230.00

BORE KIT 440cc

89mm Forged Piston, 11.2:1 Compression

Perfect for riders looking for additional torque and smooth power delivery. Smooth torque, great for tight woods riding.

INCLUDES: Sleeve, piston, pin, rings, circlips, headgasket, basegasket

REQUIRES: Re-sleeving of your cylinder, rejetting.

00314HC

$315.00

BORE KIT +.020”

OVERSIZE FOR 89mm 440cc

89.5mm Forged Piston, 11.2:1 Compression

INCLUDES: Piston, pin, rings, circlips, headgasket, basegasket

REQUIRES: Must use oversize sleeve provided with any aftermarket 89mm kit.

#00314HC-B

$225.00

BORE KIT 87mm

SHORT DECK HEIGHT FOR 4mm STROKE

87mm Piston, 11.5:1 Compression

Works with any +4mm stroked crank and standard-length rod (piston is 2mm shorter pin-to-deck). Skirted for crank and balancer clearance.  This is the piston we sell with our regular 440cc Bore & Stroke combo.  You can use it as a replacement for that kit, or with other aftermarket +4mm stroker cranks.

INCLUDES: Piston, pin, rings, circlips, headgasket, basegasket

REQUIRES: +4mm Stroked Crank (not included), Boring, rejetting.

#00302S

$272.00

STROKER +4.0mm W/ ‘TOUGH ROD’

 SHORT ROD - USE ANY 400EX PISTON!

425cc with stock piston, 440cc with 87mm piston, 460cc with 89mm piston

Stroker only, piston kit not included.

This stroker utilizes our super-strong Falicon-built ‘Tough Rod’ (with your stock pin and needle assembly).

The shorter rod allows you to utilize any 400EX piston kit (piston skirt may need to be shortened with brands other than Powroll) and does not require any case or gear modifications.

INCLUDES: New Powroll Tough Rod. Stroke work done on your crank. 

REQUIRES: Your crank pin and needle assembly must be good.  Non-Powroll pistons will need modification to skirt.  Send in your crank for modification.  Download our Stroker Booklet for details.

#16092R

$545.00

440cc BORE & STROKE COMBO

87mm BORE, +4mm STROKE, 11.5:1 COMPRESSION

This kit provides great overall power increases, with excellent torque and strong pull throughout the power range and very quick rev.  Re-uses your stock rod assembly, so your rod must be good.

INCLUDES: 87mm Bore-In Piston Kit: Piston, pin, rings, circlips, headgasket, basegasket. 4.0mm Stroke, work done on your crank.

REQUIRES: Cylinder boring. Rejetting. Send in your crank for modification.  Download our Stroker Booklet for details.

Note:  Powroll will not install aftermarket rods (other than our Tough Rod shown above) on 400EX cranks - your crank must have a good stock rod assembly (rod, needle assembly and crank pin).  Rod components are not available from Honda (only complete crank assemblies).

#00302S-16094LR

$522.00

CAMSHAFT - RACE GRIND 

On your core, or purchase outright

Lift .350” Intake and .345” Exhaust

Excellent mid to top end increase when used with any of our bore kits or bore and stroke combinations.

This cam has a noticeable increase in top-end power when used with a 440cc or larger displacement engine.

REQUIRES: Send in your good cam core for refund. Hardfaced rockers. High Performance valve springs.

#12745

On Your Core (send your core for work) $195.00

Purchase Outright $365.00

ROCKERS - HARDFACED

HARDWELD , Done on your cores

Highly recommend with any aftermarket camshaft.

REQUIRES: Send in your good rockers for work, 3-4 week turn-around.

#23001

$280.00 on your good cores

VALVE SPRINGS

Recommended for use with all high-lift 400EX camshafts.

INCLUDES: Stronger inner and outer springs. Titanium Retainers.

#24035

$120.00

VALVES - STAINLESS STEEL

Increased longevity and better airflow characteristics make these a much better deal than OEM replacements.

Valves are sold as a set.  Purchase 1 set of Intake Valves and 1 set of Exhaust Valves for a complete set of 4.

CARB - 39mm KEIHIN FCR

POWROLL SPECIAL SET

This flat-slide pumper carb works exceptionally well throughout the rpm range of the engine, from just off idle to screaming at peak horsepower. With unbelievably crisp throttle response, there’s no other carb that can duplicate it’s performance in a four-stroke (that’s why they come stock on modern four-stroke race bikes and quads.

Kit Includes:  Prejetted Keihin 39mm Carb with airboot adaptor to work with your stock airbox, custom single throttle cable for use with thumb throttle, additional main jet sizes, installation and jetting instruction booklet.

Recommended For:  Racing and dune engines 415cc and larger.  Trail engines 440cc and larger.

#20530

$600.00

WHY PURCHASE YOUR FCR CARB FROM POWROLL?

The complex design of the FCR makes setup very important. Every FCR carburetor that Powroll sells goes through a 30-point inspection. Jetting is set for the application, the pump stroke is calibrated; almost an hour of work goes into each of our FCR carbs. You also receive our FCR carb tuning booklet. All this adds up to a carburetor that is truly a ‘bolt on and ride’ setup!

WILL YOU TUNE MY FCR CARB I PURCHASED FROM ANOTHER SOURCE?

Due to the huge variety of possible setups for this carb, we are not able to offer this service.  It is very important to purchase your FCR carburetor from a reliable source - the best option is to purchase your carb from the same company that built your other performance parts.  If you are shopping eBay to try and save a few dollars on performance goodies, buy your shiny billet bits, your exhaust system, almost anything else there -- but get your carb from a reliable source -- you'll save money, time and headaches.

CLUTCH SPRINGS - PERFORMANCE

Recommended for all performance applications.

#16780

$21.00

IGNITION HOP UP TRICK!

Many aftermarket CDI boxes sold for the 400EX are actually stock Honda XR250R boxes.  The unmodified XR250 box will give you about 800 more rpm on top and a faster ignition curve.  You can purchase this directly from your local Honda dealer and save money.

Order:  CDI for Honda XR 250 1992-2004   Part #30410-KCE-671