BIG BORE CYLINDER KITS

Dirt Bike Big Bore Cylinder Kits – More Displacement, More Power Step up your engine's performance with our big bore cylinder kits — the proven way to add real displacement, torque, and horsepower without swapping to a different bike or engine platform. Each kit is machined to a precise...  show more

Dirt Bike Big Bore Cylinder Kits – More Displacement, More Power

Step up your engine's performance with our big bore cylinder kits — the proven way to add real displacement, torque, and horsepower without swapping to a different bike or engine platform. Each kit is machined to a precise overbore specification, giving you a genuine capacity increase backed by matched pistons, rings, and gaskets for a complete, reliable build.

Why Riders Choose Our Big Bore Cylinder Kits

• Complete Kit, Ready to Fit – Includes oversized cylinder, matched piston, rings, wrist pin, circlips, and gasket set for a full top-end installation
• Genuine Displacement Increase – Common overbore options (e.g. +2mm, +3mm, +4mm) add meaningful cc's and torque over stock
• Nikasil / Ceramic Coated Bores – Hard-wearing cylinder coatings handle the extra heat and cylinder pressure that comes with increased displacement
• Forged Piston Options – Stronger forged pistons available for riders pushing higher compression or sustained race use
• Precision Fit – Machined to correct tolerances for accurate ring seal, compression, and clean break-in
• Wide Model Range – Available for Honda CRF, Yamaha YZ/YZF, KTM SX/SX-F, Kawasaki KX/KX-F, and Suzuki RM/RM-Z
  Why Riders Upgrade to Big Bore

A big bore kit is one of the most effective ways to reshape your engine's power delivery, adding low-end torque and mid-range pull that a stock bore simply can't produce. It's a popular route for riders wanting more grunt out of corners and over jumps without the cost and complexity of moving up an entire bike class, and pairs naturally with a matched camshaft and gasket set for the full performance gain.

Perfect For

• Riders wanting a genuine power and torque increase over stock
• Racers looking for stronger corner-exit drive and mid-range pull
• Post-crash or worn-bore rebuilds using the opportunity to go big bore
• Workshops fitting complete performance-focused engine builds