YFZ 491 Stealth Big Bore/Stroker

Please call to order 608-842-0680

Availability: In stock.



Quick Overview

YFZ 491 STEALTH Specifications:
Fits 2004-2008 YFZ 450


Product Description

Bore: Yes

Stroke: Yes

Actual Displacement = 490.68cc


Choose Option:

We modify your cylinder

Exchange cylinder and crankshaft: $ 75.00

“Bolt on” – Includes cylinder and crankshaft: $ 310.00

Installed and Blueprinted: $ 500.00


Engine Modifications Included:

Cylinder: OEM Cylinder bored and plated with Ceramic Nickel Bore coating

Fuel Required: 91 – 110 octane – Options Available

Piston/Crankshaft: Wiseco or CP Piston – Max Power Extreme Coated / Aftermarket Stroker Crank – Balance recommended – Add: $250

Head: No modification required

Crankcase: No modification required


Notes: This kit is a real diamond in the rough. The first time we hit the track with this kit it really got our attention. It revs out super fast and pulls like a much bigger engine than what it is. It uses a +3mm Hot Rods crankshaft and a Max Power Ceramic Nickel Bore plated OEM 97mm cylinder. We highly reccomend getting the cranked balanced or your hands will fall asleep. We also provide a full botom end gasket and seal kit. It is basically a total rebuild kit less main bearings (and we can get you those also for a bit more) It comes in multiple compression ratios and uses either a CP or Wiesco piston – Your choice. If you got a tired YFZ, limited funds, and some mechnical skill, this kit is a pretty sweet deal that really does the trick.


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