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American V4® | Motus Motorcylces
motus, sport bikes, american motorcycles, touring motorcycles
mst, motus, motorcycle engine, mv4

The American V4® Precision with Attitude

When we began our pursuit of building the ultimate American sport-touring motorcycle, we quickly realized the ideal engine didn’t exist. So we built it.

The mighty Baby Block® MV4 is a pushrod powered V4 that delivers massive torque across a wide, smooth power band. It speaks with an exhaust note unlike anything before it. Equally important, the American V4® uses known technology proven to be durable and easy to maintain. It's the same small block architecture found in the most reliable and competitive engines on the planet from popular American passenger cars and trucks to high performance racing vehicles.

Of course, some people want it for small race vehicles and other motorcycles, but the MV4 may also be perfect for other applications. If you are interested in a crate engine, we’d love to talk about your ideas.


  • 1650cc (100ci)
  • Liquid-cooled
  • 90° V4
  • 2-valve
  • Cam-in-the-block
  • Pushrod
  • Maintenance-free hydraulic roller lifters
  • Wet sump
  • Closed loop multi-point fully sequential fuel injection
  • Ride-by-wire electronic throttle control (ETC)
  • 12 bolt bell housing (9.5” bolt circle)
  • 4 x 40mm downdraft throttle bodies
v4 Dyno Chart
  • 410mm (16in) long x 516mm (20.3in) wide x 667mm (26.25in) high
  • W/gearbox 658mm (26in) long x 516mm (20.3in) wide x 714mm (28in) high
  • Bore/stroke: 88mm (3.465in) bore x 67.80mm (2.669in) stroke
  • Valves: Intake 46.5mm (1.831in), Exhaust 38mm (1.496in)
  • V4 wet weight: approx. 150 lbs
  • V4 with gearbox wet weight: approx. 102 kg (225 lbs)
  • 6-speed gearbox, dual overdrive
  • Gearbox wet weight: approx. 34 kg (75 lbs)
  • Side access wet clutch, hydraulically actuated
  • Competition grade, investment cast steel clutch basket
  • Serviceable cassette-style gear cluster
Gear Ratios
Gearbox Final (16T/41T)
1 2.07 9.01
2 1.53 6.65
3 1.21 5.26
4 1.00 4.35
5 0.87 3.78
6 0.76 3.30