Vortex Rok Shifter Engine

  • Sale
  • Regular price $3,500.00 *In Stock

The Vortex Shifter engine sets the bar at a monster 43 hp all while delivering famous Vortex ROK reliability. A racing front-clutch 6-speed gearbox is at the heart of this 125cc kart engine. With a 4 reed intake valve, water cooling by external water pump (not included), Dell’Orto VHSH Ø 30 mm fuel delivery, fuel pump, electronic ignition, and racing exhaust with silencer. Once again ROK has delivered an industry leading motor with affordable pricing and great reliability. 

This package is for drivers competing in the Vortex ROK Shifter Kart classes. That being said many racers love to use this engine for fun karts. 


  • Liquid-cooling via external water-pump
  • Racing exhaust with rwo booster setup
  • C4 radial bearing design
  • 54x54.5 mm bore/stroke
  • Peak horsepower is 43 HP at 13,900 rpm
  • Peak torque at 14,000 rpm
  • Dell’Orto VHSH Ø 30mm carburetor
  • Arrow brand intake silencing
  • Magnesium motor mounting
  • Rok Shifter racing pipe

2016 Vortex Shifter Kart Racing World Championships

You can also learn more about the 125 2-stroke concept behind the Vortex shifter engine over at how stuff works. Jetting for the proper fuel mix is crucial for tuning any 2-cycle motor. One of the most important factors is air density on any given day at the racetrack. Learn more about how air density effects performance here. Another very important consideration for the power and reliability of your Vortex shifter engine is the fuel to oil mixture. Here is a handy calculator to help you with setting the right ratios when you mix your gas and lubricant. Check out our Mini Motors and our Rok GP.