300cc KIT - AMA-LEGAL

Standard Bore, 69.5mm Stroke, 11.5:1 Compression

300cc KIT ORDER:

● PISTON KIT #00359
● STROKER #16053 (250X) -or- #16054 (300ex)
● CAMSHAFT #12733

● HARDFACE ROCKERS #23004
● VALVE SPRINGS #24029
● AIRBOX LID #46001

350cc PREMIUM KIT  -  WORCS CLASS LEGAL

● TRX 250X = 80mm BORE, +12.7mm STROKE, 11:1 COMP

● TRX 300EX = 80mm BORE, +4.5mm STROKE, 11:1 COMP

With an awesome power increase of over 80%, this kit runs strong and still has great longevity.

REQUIREMENTS: Rejetting. Your cylinder and cases will need to be modified (cylinder re-sleeving and case machining). Send you crank for modification.    Stroke work done on your good stock crank, additional parts, if needed, will be extra.

RECOMMENDATIONS: Engines operating at or near sea level may run better with a race gas mix. Powroll recommends either a White Brothers (Vance & Hines) or a Supertrapp IDS2 complete exhaust system.

350cc KIT ORDER:

● BORE KIT #00298
● STROKER #16053 (250X) -or- #16054 (300ex)
● CAMSHAFT #12733
● VALVE SPRINGS #24029
● HARDFACE ROCKERS #23004
● VALVE SPRINGS #24029

● CARB KIT #20526
● AIRBOX LID #46001

74mm High Compression PISTON KIT

Standard Bore Forged Piston, 11:1 Compression (11.5:1 w/ Stroke)

●  TRX 250X = 247cc

●  TRX 300EX = 281cc

Piston is skirted and ready to work with our stroker crank, where it gives the best possible power at 300cc's.  Small boost in throttle response for a stock engine. 

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

78mm BORE KIT  -  Choose 10.5:1, 12:1 or 13:1 Compression

●  TRX 250X = 274cc

●  TRX 300EX = 313cc

Great increase in overall horsepower.

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

REQUIRES: Resleeving of your stock cylinder. Rejetting.

RECOMMENDATIONS: Compression ratios 11:1 and higher require Race Gas, 110 octane or greater. 300EX starter may not work with compression ratios over 11:1.

80mm BORE KIT -  80mm Forged Piston, 10.5:1 Compression

●  288cc’s for the 250X

●  329cc’s for the 300EX

Great increase in overall horsepower. Designed specifically to work with our stroker cranks (but can also be used alone).

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

REQUIRES: Resleeving of your stock cylinder. Case machining to accept larger sleeve. Rejetting.

00298 H BORE KIT 80MM -- $315.00 Quantity

TRX250X

12.2mm STROKER (total stroke 69.5mm)

●  299cc w/ 74mm Piston

●  333cc w/ 78mm Piston

●  349.4cc w/ 80mm Piston

Excellent increases in torque and midrange power. Uses your good stock rod assembly (replacement Vesrah rod available for additional cost).

INCLUDES: Work done on your good stock crank, additional parts, if needed, will be extra.

REQUIRES: Send in your crank for modification. Parts, if needed, are extra.  Download our Stroker Booklet for details.

RECOMMENDATIONS: Works best with Powroll pistons. Modifications may be required if using other piston or cam brands.

TRX300EX

4mm STROKER (total stroke 69.5mm)

●  299cc w/ 74mm Piston

●  333cc w/ 78mm Piston

●  349.4cc w/ 80mm Piston

Excellent increases in torque and midrange power. Uses your good stock rod assembly (replacement Vesrah rod available for additional cost).

INCLUDES: Work done on your good stock crank, additional parts, if needed, will be extra.

REQUIRES: Send in your crank for modification. Parts, if needed, are extra.  Download our Stroker Booklet for details.

RECOMMENDATIONS: Works best with Powroll pistons. Modifications may be required if using other piston or cam brands.

16054 H STROKE 300EX 4MM -- $290.00 CLICK TO APPROVE I am shipping my crank to Powroll for modification. I have read the General Product Info Page. Quantity

CAMSHAFT - TORQUE - HARDWELD (INCLUDES CORE CHARGE)

Lift .304” Intake, .304” Exhaust.

Good drop-in grind for stock or mildly modified engines.

REQUIRES: Send in your good cam core for refund.  Uses your bearings.

CAMSHAFT - PERFORMANCE  - HARDWELD (INCLUDES CORE CHARGE)

Lift .336” Intake, .336” Exhaust.

Designed for use with big bore and/or high compression engines.

REQUIRES: Valve Springs #24029.  Send in your good cam core for refund.  Uses your bearings.

12733HW-22733G CAM (Price incl. core crg of $90.00) -- $270.00 Quantity

ROCKERS - Hardfaced Rockers  - Done on your cores

Designed to work with all aftermarket camshafts.  Highly recommended in any performance engine.

REQUIRES: Send in your good cores for work.  Turn-around is approximately 4 weeks.

VALVE SPRINGS WITH TITANIUM RETAINERS

Designed for use with high lift camshafts

INCLUDES: Inner and outer springs, titanium retainers, shims

24029 H VALVE SPRINGS 250X-300EX -- $120.00 Quantity

32mm MIKUNI ROUND SLIDE CARBURETOR

Pre-jetted for our 350cc kit.

INCLUDES:  Pre-jetted carburetor, extra jets, twist throttle assembly

20526 H CARB KIT 32MM -- $280.00 Quantity

Powroll does not currently manufacture a system for this model, but recommends the following complete exhaust systems for use with our performance modifications for the 250X & 300EX:

●  Supertrapp

●  White Brothers (Vance & Hines)

SALE!  CLEAR VENTED AIRBOX LID
Developed with intensive research and race proven. Install the Powroll vented lid and experience a significant increase in airflow without the filtration problems common when running without a lid. Clear plastic so you can check your filter without removing the lid!