POWROLL PRODUCTS FOR THE YAMAHA YZF & WR 426

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Powroll

13840 Commercial Lp

Crooked River, OR

97760

Mail:

PO Box 920

Redmond OR 97756

Phone

541-923-1290

Fax

541-923-5637

Email

Powroll - 4 Stroke Performance

Designed for the 426, this kit will also work for the YZF & WR 400, check the information listed below for information on how to make your 400 into a 426 or a 440!

STROKER +2.0mm

YZF426 & WR426

(and 400's with parts listed below)

#16091

$400.00

440cc’s. Works only with stock Yamaha Piston.

Awesome increase in low end and midrange power.

Excellent for long sandy tracks, with more torque than a CRF!

The perfect choice for woods riders or just someone looking for the ultimate in quick-revving power. We stroke your stock crank assembly, and modify your new OEM piston.

INCLUDES: Work done on your crank and piston.

REQUIRES: Send a new Yamaha OEM piston for modification. Send in your crank for modification. Download our Stroker Booklet for details.

RECOMMENDATIONS: For engines with over 200 hours of use, we recommend replacing the rod assembly.

YZF 400 & WR 400

Powroll doesn't sell these parts - order from your Yamaha dealer.

These first-generation F's can be easily upgraded to 426cc with stock Yamaha parts -- or to 440cc's with the parts listed, plus our 2.0mm stroker listed above.

A weak point on the 400 is the smaller piston pin. Upgrading to the 426 parts gives your engine better reliability for the same (or cheaper) prices than purchasing these parts aftermarket.

You can have your 400 cylinder bored and re-nikasiled, but this process typically costs more than the cost of a new 426 cylinder.

To build your 400 to a 426:

1. Purchase every item shown on the list to the right. Check online from Yamaha of Troy, or your local dealer.

2. Your 400 crank will need to be rebuilt with the new 426 rod and needle assembly. Powroll can provide this service, call us at 541-923-1290 for current pricing.

To build your 400 to a 440cc:

1. Purchase every item shown on the list to the right. Check online from Yamaha of Troy, or your local dealer.

2. Order the 440cc work above, then send us your 400 crank, along with the blue highlighted items shown in the list to the right.

Qty	Part Number	Description
	5BE-11681-00-00	YZF 400 CRANK PIN
	93310-634B0-00	YZF426 CRANK BEARING
	5JG-11651-00-00	YZF426 ROD, CONNECTING
	5JG-11631-10-00	YZF426 PISTON (STD)
	5JG-11603-00-00	YZF426 PISTON RING SET (S
	5JG-11633-00-00	YZF426 PIN, PISTON
	93420-19084-00	YZF426 CIRCLIP
	5JG-11181-00-00	YZF426 GASKET, CYLINDER H
	5BE-11351-00-00	YZF426 GASKET, CYLINDER
	5JG-11311-00-00	YZF426 CYLINDER 1

Why don't we offer this kit for the 450? Space inside the new engine doesn't allow for a safe increase in the stroke, as the rod would have to be made thinner than acceptable limits to clear internal engine components and the bottom of the crankcase.

Powroll Motor Performance

13840 Commercial Lp Crooked River, OR 97760 Phone (541) 923-1290 Fax (541) 923-5637

Descriptions and pricing are subject to change without notice.