O.S. Speed 12XZ Spec III

O.S. Speed 12XZ Spec III

Brand: OS Engines

Part Number: L-OS11685

£302.93 Web Price RRP £329.99

Out of stock

Request Stock Notifcation

Request Price Match


O.S. engineers have taken superior performance to the next level! In addition to smoother acceleration from idle to full throttle, the 12XZ Speed Spec III also has increased low-to mid-range torque. Drivers will still enjoy the same impressive top end speeds that 12XZ Speed Spec engines are known for — with the bonus of improved fuel economy. In fact, acclaimed on-road champion racer Takaaki Shimo utilised all of the 12XZ Speed Spec III’s advantages to claim victory in the 2012 Japan Nats!

The cylinder liner’s outer diameter is slightly thicker (0.5mm), resulting in redesigned port angles for better air/fuel flow. The piston features a tapered surface with a depression in the middle to work better with the head button. The crankshaft features DLC coating, a pressed-in Tungsten weight and ceramic rear ball bearing. The outer head is 1mm shorter and sits 6mm lower over the crankcase, for less overall weight while also lowering the CG. The new 12F2(B) carburetor delivers sharp acceleration and instant throttle response.

• Redesigned head for higher performance and improved acceleration.
• New cylinder liner and piston improve mid speed torque and fuel economy
• The slide valve’s shape allows for a smoother flow of fuel and air
• Ceramic rear ball bearing
Weight 225g (7.9 oz)
Displacement 2.1cc (0.128 cu.in.)
Bore 13.8mm (0.543")
Stroke 14mm (0.55")
Power Output 1.73 hp @ 35,000 rpm
Practical RPM 5,000 - 44,000
  • Brand: OS Engines
  • Part No: L-OS11685
  • Displacement: 2.1cc (0.12ci)
  • Starter: Flywheel Start

Free UK Delivery!

This item is over £100, so qualifies for free standard UK shipping!

We Ship Worldwide!

To see shipping costs simply add the item to your basket and choose your country from the drop down list on the view cart page.

No reviews yet!

Write a Review
No questions yet, why not ask one?
Ask a Question