2023-2026 YAMAHA YZ450F 99MM BIG BORE & 6MM STROKER CRANKSHAFT KIT

Description

This kit offers significant gains in horsepower and torque with a 6MM Stroker crankshaft and 99MM Bore utilizing a 15.1 compression ratio piston. This kit increases your engine’s displacement to an impressive 514cc. We designed this kit to be a simple drop-in solution, no case modifications required, no spacer plates or longer chains needed!

Product Specifications:

• Stroke Increase: Adds 6MM to the engine stroke, making it 66.8MM
• Balanced Crank: The crankshaft is heavy metal balanced to accommodate the new reciprocating weight of the assembly, no vibrations!
• Assembled and Trued: The crankshaft is pre-assembled and trued for optimal performance
• Crank Pin: Welded to prevent twisting
• Bore Size: Features a 99MM bore piston, resulting in an engine displacement of 514cc.
• Drop-In System: Designed for simple installation without the need for any other modifications
• Cylinder: Bored and honed to 99MM
• Gaskets: Includes 99mm head gasket and cylinder gasket
• Piston and Cylinder Bore Size: 99MM
• Piston Features:
  • 15.1 Compression Ratio Piston with Vertical Gas Ports
  • Titanium Nitride Treated Rings
  • DLC Coated Wrist Pin
  • Circlips

• Core Options: Please select one of the following core options to place and online order:
  1. Crankshaft Core and Cylinder Core supplied by Buyer: $2299.95 – You send us your crank and cylinder and we complete the work required. Stroking/Balancing and Boring/Replating. Turn around time is 4-6 weeks.
  2. Crankshaft and Cylinder Core Exchange: $2299.95 You send us your crankshaft and cylinder cores. Once we confirm they are in useable condition we send you our completed kit. Turn around time is 1 week. (WHEN IN STOCK! Otherwise 4-6 weeks)
  3. Crankshaft Core and Cylinder Core supplied by Dynamic: $3299.95 We sell you a new crank and cylinder with all the work already completed and you don’t send us anything. Shipping time is 2-3 days when in stock!

Shipping:

• If supplying a crankshaft and cylinder core, print your order form, package and ship your crank and cylinder to us so we know who’s it and who to contact.

NOTE:

• PLEASE INSPECT PISTON SKIRT TO COUNTER BALANCE SHAFT CLEARANCE.
• If you have any questions about this kit or the process, please contact us.