Vortex ROK VLR 100cc Kart Engine – 20hp Air-Cooled 2-Stroke with Electric Start

The Vortex ROK VLR was designed for club racers: new drivers getting into karting, and racers moving up from a four-cycle engine or replacing an older 100cc. It is easy to operate, easy to maintain and easy to inspect, and it adds electric start at a price club racers can afford. It comes complete and ready to race, minus the engine mount.

Where you can race it

The VLR is used in the Junior VLR (ages 12-15), Senior VLR (ages 15 and up) and Masters VLR (ages 32 and up) classes. Vortex builds a standard VLR and a VLR-J with a manifold restrictor for junior classes, so check your series rulebook and contact us to confirm which version you need before ordering.

Main features

• Single-cylinder 2-stroke, 98.53cc, with a reed-valve intake
• Air-cooled, with mixture lubrication
• Integrated electric starter, with an on-board generator for battery charging
• Centrifugal dry clutch
• Cast iron cylinder liner with 3 transfer ports, 1 elliptical exhaust port and 2 boosters
• Selettra analogic ignition

What’s included

• 24 mm butterfly-valve carburetor
• Vortex intake silencer
• Exhaust with flex pipe and silencer
• Generator for battery charging, and electric starter fitted on the engine

Prime Bike Parts tests its products before they ship, and we ship securely to almost all countries. Check your series rulebook to confirm this engine is legal for your class, and contact us if you need help with fitment or setup.

Type	Single cylinder, 2-stroke
Displacement	98.53 cc (100 cc class)
Bore x stroke	48.20 × 54.00 mm (1.898 × 2.126 in)
Compression ratio	10.5:1
Intake	Reed valve
Ports	3 transfer; 1 elliptical exhaust plus 2 boosters
Cooling	Air
Lubrication	Mixture
Ignition	Selettra analogic
Starter	Integrated electric, with on-board charging generator
Clutch	Centrifugal dry clutch
Carburetor	24 mm butterfly valve
Intake silencer	Vortex
Max power	20hp @ 9,800 rpm
Max torque	13.7 N·m (10.1 lb-ft) @ 9,600 rpm
Max rpm	16,000
Port timing	Inlet 126° ±2°, exhaust 164° ±2° (measured with a 0.20 mm feeler gauge)
Cylinder	Aluminum-silicon alloy with cast iron liner
Crankshaft and connecting rod	Nickel-chrome-molybdenum steel
Piston ring	L type
Engine weight	45 lbs
Classes	Junior VLR (12-15), Senior VLR (15+), Masters VLR (32+)