Evil Restomod: Yamaha RZ392

Yamaha RZ392

Evil RZ:  “It is a pure bred giant-killer, not for the faint of heart…”

The Yamaha RZ350 was one of the last, great 2-stroke street bikes available in the USA. The ~50 horsepower parallel twin was nothing short of wicked, and a version of the same engine powered Yamaha’s aptly-named Banshee 350 ATV.

Yamaha RZ392

Enter Lou Voiler, a self-proclaimed 2-stroke fanatic from Southern California who decided to build his ’85 RZ350 into an evil, bloodred restomod like none we’ve seen, capable of putting newer bikes to shame.  Lou spent years dialing the bike in just the way he wanted it, with a wide arsenal of parts to enhance the bike’s suspension, braking, and aesthetics. He built the bike himself except for the engine, turning to one of the great 2-stroke wizards, Roger Arreola of California’s Wicked Motorsports ATV

“A well known Banshee builder who’d cast his evil eye toward RZ engines the last decade or so.”

The result is a 392cc, 2-stroke, 81.6-rwhp street weapon that Lou rides every weekend. Below, we get the full story on this evil restomod.

Yamaha RZ392 Giant-Killer: Builder Interview

Yamaha RZ392

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

Southern California native, two stroke fanatic. Bought the RZ in this submission stock in 2001 w/1900 miles. Built it from the ground up. Also ride a 2008 Ducati Hypermotard 1100s. Over the years, I built the suspension the way I liked it, got it dialed in, and finally went to the source for a bad-ass power plant. I have done a lot of research and one guy kept showing up: Roger @ Wicked Motorsports, a well known Banshee builder who’d cast his evil eye toward RZ engines the last decade or so.

Yamaha RZ392

• What’s the make, model, and year of the bike?

Which part? 🙂

Platform is an ’85 Yamaha RZ350, Red/White/Blue Kenny Roberts Special.

Yamaha RZ392

• Why was this bike built?

Because I rode it pretty hard and every time I crashed it, I tried to improve it when I put it back together. I finally just decided to build it exactly the way I wanted it as a rider. I wasn’t really concerned about the paint and how it looked, just how it rode. The paint was an afterthought. I decided to make it a stock theme that only true RZ aficionados would recognize as a color not offered; I thought Yamaha missed the mark never making a red RZ, so I did. I never expected that people would respond to it the way they have. There is a large contingent of fire-breathers out there that want to bring two strokes back.

Yamaha RZ392

• What was the design concept and what influenced the build?

Modern suspension/wheels/rubber/power without losing its original look, personality, or fun factor, but rather enhancing them: Giant-killer on steroids.

Yamaha RZ392

• What custom work was done to the bike?

OK. Here we go:


  • ’91 Honda NSR250 MC21 rear wheel
  • Milled and Polished sprocket carrier
  • Dunlop Q3 160/60X17
  • Brembo Front Trials Brake on rear wheel
  • One Off Brake hanger
  • JMC eccentric underbraced swingarm
  • Fox Racing fully adjustable rear shock
  • Tarozzi rear set
  • NHK Damper
  • ’94 Honda F2 forks w/Traxxion Dynamics cartridges
  • EBC caliper relocators
  • EBC oversized rotors
  • Vortex clip ons
  • 2014 Triumph Thruxton flyscreen/headlamp bucket
  • One off front fender
  • Motosign LED idiot lights/indicators
  • Aftermarket Harley gauges/bracket
  • Sargeant solo seat/cover
  • Toomey battery box
  • One off red, white, black paint/graphics
  • Grab bar removed/filled.
  • Kickstand spring/post moved to outside to accommodate exhaust
  • Kickstand lengthened to accommodate raised ride height


  • Wicked Motorsports +5mm billet stroker crank/Long rods: 392cc
  • Race/play porting, case match
  • Wicked Motorsports YPVS cool head
  • V-Force 4 cage/reeds
  • Wicked Motorsports Banshee/Rz crossover oil injected intake manifold
  • Keihin PWK 39mm carbs
  • Wicked Motorsports oversized float bowls
  • Wicked Motorsports Clutch Basket/anti-seize pusher
  • Shift Pro kit
  • +4 timing plate
  • 2008 Yamaha R6 quick 1/6 turn throttle
  • Banshee over frame throttle cable
  • American Volt fan
  • Samco hoses
  • Mechanical oil tank sensor
  • 3/8” offset -1 countershaft sprocket
  • Wicked Motorsports 3-piece billet stator/countershaft sprocket cover
  • Wicked Motorsports billet clutch and oil pump cover
  • K & N filters
  • Wicked Motorsports one off oversized O-ring exhaust, stingers and silencers
  • Gravity-feed petcock
81.6 RWHP!
• How would you classify this bike?

Evil Resto-mod.

Yamaha RZ392

• Was there anything done during this build that you are particularly proud of?

I built it to ride it and ride it hard, though I make sure to treat it like a grown-up and it seems to return the favor. It is a pure bred giant-killer, not for the faint of heart. It treats you the way you treat it. I make sure not to ask it any questions to which I don’t really want to know the answer. It’s not a show bike, it’s a beast and it puts a smile on my face as well as it terrorizes my friends w/big modern bikes every weekend.

Yamaha RZ392

Hear it Rip!

Ridden by engine-builder Robert of Wicked Motorsports…

Detail Shots

Yamaha RZ392  Yamaha RZ392

Follow the Builder

Except for the engine, I built the bike myself.

The engine builder is Roger at Wicked Motorsports in Garden Grove, CA. He is hands down the man for all things two-stroke and fast. Has his own CNC machines and can make ANYTHING!




  1. That’s very very cool! I’d love to see one of those turned into a Supermoto.

  2. That is so totally radical, it’s unbelievable!

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