The riding season is short in Toronto, with snow on the ground for three or four months of the year. But that leaves plenty of time for wrenching in the garage or workshop, so there’s a low-key but thriving custom scene.
Canada’s biggest city is home to Brian Kate of Motobrix, who recently finished this piping hot Kawasaki triple called El Citron.

Brian was a late starter, although you’d never tell from this build. “I didn’t work on bikes or cars as a kid, or even do anything hands-on until I was in my late 20s,” says Brian. “I’m 34 now.”
His saving grace is a degree in Mechanical Engineering and a Masters in Biomedical Engineering. “I got interested in customizing my first bike while working as a researcher at a hospital; I bought an SV650 and tried to make it look more like a Ducati Monster.”

“I studied other people’s work on forums and asked questions, and broke a lot of tools and parts by learning and doing things the wrong way. I eventually took some welding courses at a local college and from there kept teaching myself how to wrench and fabricate.”
In 2014 Brian took a leap. He quit his job, developed his skills as a fabricator and bike builder, and started Motobrix.

He bought this 1974 Kawasaki S3 from a friend. It’s a 400cc triple two stroke, temperamental but supposedly not too difficult to deal with…
El Citron was at times a difficult bike to build though, because I had to move workshops,” says Brian. “I ended up in three different locations throughout the build.”

The process of building the triple also became a can of worms.
“I read up on the history of Kawasaki triples and the ‘widow maker’ nickname, and was excited to work on one,” says Brian. “But when I picked the bike up and rode it home, I barely got down the street before it stalled.”

“I finally got home with the bike spewing out black oily goo from the exhausts all over my parking space. My friend joked about how he’d suckered me into buying a complete basket case!”
Was the bike a lemon? Well, the tank was already yellow—so Brian decided on the name El Citron. “I wanted to turn the S3 into something modern and sporty, while keeping the character of an old two-stroke.”

At the front, the forks and wheel from a GSX-R600 set the tone, with a steering stem from Cognito Moto to make everything fit.
The headlight sits tight against the fork stanchions. “I noticed that some new LED headlights are fairly flat, and tried to figure out a way to mount one of them without using the stock off-the-shelf buckets,” says Brian. With the help of Rusty Girl, a metal artist, the light was fixed with an orbital mount.

At the back Brian’s chosen a Suzuki Bandit 600 swingarm, because it has a narrow pivot width— and permits the use of a 160-width tire. For the monoshock, he’s picked a GSX-R1000 unit for the look and shape.
“For the mounting points, I set the bike up with roughly the right rake for what I wanted, and fabricated mounts based on where the shock needed to sit. As much as I’m an engineer, sometimes I rely on eyeballing and intuition.”

It wasn’t an easy job. “I had to space the rear wheel more to one side, rather than rewelding the frame. After spacing the wheel, I had to reweld the brake stay slightly offset, and then had to find a way to prevent the chain from rubbing on the tire,” he recalls.
“I looked to the supermoto forums for a plan, since they often try to fit fat tires on skinny bikes. I used a 10mm offset sprocket in the front, a GS500 sprocket carrier to align the chain properly, and then welded on a bracket for a nylon chain guard to prevent rubbing.”

“The bike essentially became an eBay parts bin Kawazuki!” But even with all these changes, Brian decided to go with a 150 tire instead of a 160 to give a bit more clearance.
With help from his friend Roger Leavens, Brian took the S3’s engine apart and found that everything was in pretty bad shape. “The kickstart lever had been welded to the shaft, and many of the bolts were stripped from previous rebuilds.”

The crankshaft went to Triple Cranks in Maryland for a rebuild and balancing. The badly scored cylinders went to Gord Bush Performance in Toronto, where they were bored a millimeter oversize and fitted with a new set of Wossner forged pistons. And Jeff Derstine in Pennsylvania rebuilt the oil pump.
Meanwhile, Brian cut and replaced the stock subframe with a sand bent handmade section. He stole the rearsets from his old SV650, and made up brackets to weld them to the frame.

For the two-stroke oil reservoir, Brian welded up a mini chopper-style oil tank. He’s upgraded the battery to a tiny Shorai lithium unit, which sits just under the seat near the tail. (“With kick only, the battery doesn’t need many cranking amps.”)
Exhaust systems are obviously critical on two-strokes, so Brian invested in a magnificent set of secondhand Higgspeed expansion chambers. “I had to reweld one of the outer pipes to fit properly with the wider swingarm,” he notes.

“The rearsets sit a bit high because of the exhausts, and the shifter lever was hitting the exhaust. So I cut and welded the lever in a more outward position.”
By now Brian was four years into the build, working on the triple between client projects. All that was left to do was paint the yellow gas tank, which has been finished by Amanda from Black Widow Custom Paint.

“It’s been a bit of a love-hate relationship,” Brian admits. “It never failed to give me challenges, but it’s always been one of my favorite projects.”
But as they say, when life gives you lemons, make lemonade. And Brian’s yellow S3 is a refreshing departure from the custom norms—the moto equivalent of a glass of tart, ice-cold soda on a hot summer’s day.
Motobrix | Instagram | Images by Mark Luciani