Yamaha RD400 custom

Yamaha RD400 custom
Today’s post is courtesy of Moto Retro Illustrated magazine, with words and photos by Andy and Lindsay Mauk.

To some, acquiring a bike for your wife might sound as simple as buying her a set of golf clubs, or maybe adding some space to the garage as an anniversary gift.

But this was different. Way different. The request came from my wife Lindsay loud and clear. “I need a bike I can ride on the street,” she said. It was true. After years of riding dirt and racing supermoto, Lindsay was neither content nor deserving of a sissy-bar lifestyle. She needed her own streetbike.

While most people would’ve simply headed straight to the classifieds, my instinct was to put together something we already had. A quick search of my mental catalog turned up the answer—a ’78 RD400 my buddy John used in college and had “stored” in a barn to rot.

Lindsay and I went to grab the barn-fresh bike. It’d been a few years, so I wasn’t sure what to expect. I think Lindsay was just excited to pick up her new ride. But here’s where some of the story details changed. “Stored in a barn” turned to “stored outside a barn.” And “seized engine” morphed into “single-piece crankshaft made of rust.” It was ugly, and we hadn’t even found the cylinders yet. After some hunting and gathering we loaded everything up and headed home, with a stop at a local carwash to rid the bike of multiple layers of bat guano.

Step one was to be this: Strip bike completely, rebuild engine, and repaint chassis and bodywork. Then reassemble. Step two: Present bike to Lindsay and go riding.

Yamaha RD400 custom
But somewhere between steps one and two the plan changed, the change brought on via a call to my buddy Rick Goldberg.

Me: Hey Rick, I’m gonna put John’s RD together for Lindsay. Wanna help?
Rick: “Sure! Bring it to the shop. Sounds like fun!

Rick’s shop isn’t extravagant, just an attached two-car with no cars, but it did have some cool tools—metal lathe, welder, mill, and other fabrication bits. The problem here is that Rick really likes to use his tools, and suddenly we’d gone from “restore” to “re-engineer,” the photo of a Ron Wood YZ400 dirttracker on his wall providing some direction. With a concept in mind and a tight schedule to adhere to (Lindsay wanted to be riding by spring), we got to work.

As with most of our projects, the dual MOMBA experiences being two of the most recent, work began on the chassis. Rick and I cast longing looks toward the Sawzall—Milwaukee’s finest “cut-anything” tool—hanging on the wall, but first we needed parts. Rick’s shop already contained a dirt-track tail section and fuel tank, which helped provide an image of what we were actually about to create. Other than those bits, everything else was yet to be determined. I had some old RZ350 rotors left over from my early roadracing days, and we thought they’d work fine, especially bolted to RZ wheels, which of course we didn’t have. A quick call to friend and two-stroke connoisseur Dan Slattery and JACKPOT! Dan not only provided wheels, but an RZ fork, triple clamps, swingarm, brakes and a set of worn-but-workable Toomey chambers.

Fitting the RZ front end was relatively easy. Upper triples bolted right on with new tapered bearings, Progressive springs were installed to keep it taut, and a Kawi ZX-7 master cylinder provided the right valving for the RZ brakes—more than enough braking force there.

Yamaha RD400 custom
In back, the RZ swingarm bolted up just fine with some trimming (Sawzall!). We’d planned to simply weld on some shock mounts, but Rick, having just read Tony Foale’s Motorcycle Handling and Chassis Design book, convinced me that a monoshock system was the way to go. A quick scavenge of parts revealed a tub full of dog-bones and hardware, and an FZR600 shock. A couple sketches, some concept overview and a small leap of faith later we were grinding, cutting (Sawzall!) and mounting our way to a mono-shocked, RD400 heaven.

The monoshock system also allowed us to simplify and lighten the bike’s chassis even further. Without the need to hold the upper shock mounts, the subframe need only hold Lindsay, so the Sawzall came out again and the stock subframe was gone, a slimmer, trimmer sub taking its place. One of my favorite features on this bike is the “see through” effect in front of the rear wheel.

With the chassis done, the final major cosmetic piece—the fuel tank—remained. The stock RD tank was way too big, so we needed another, and shortly found another, smaller Yamaha tank that worked perfectly with some minor fabrication. To this day we have no clue what model it’s from.

Then we dug into the engine. Cases were stripped and coated, and after Supreme MOMBA Wes Orloff donated an old RD ex-race engine from his early racing days, we had plenty of good-condition internal parts, including cylinders and crank. In addition to the 350 engine’s upgrades, the Toomey exhaust and some Emgo K&N knockoffs, the motor is basically stock. I put an equalization tube between the two air filters to keep it running smooth, and jetted it to accommodate the pipes and filters. Porting is stock, as is the tranny. The almighty dollar kept us on a cheap path with the engine, but five years after the fact, it still runs like a champ.

Yamaha RD400 custom
The bike is loud, still riding and peaky. Wheelies are practically unavoidable (and a big fine here in Milwaukee), and you wouldn’t want to spend more than an hour on it. But it is an awesome ride. It attracts a sh*tload of attention wherever it goes, and I never get tired of looking at it. It’s held up throughout the years and has inspired many more projects. In 2005 it took home the “Cool As [email protected]#” award at our local Rockerbox streetparty.

Lindsay agrees. “I absolutely love that bike,” she says. “And to think all I wanted was a streetbike that was fairly clean and reliable.

“I watched this bike get built,” she adds, “so I was accustomed to the shapes and the silhouette. But nothing could have prepared me for the outcome. I was shocked! Rick and Andy went above and beyond the call. I am always honored to ride this bike—it’s beautiful, fun and totally kicks ass!

“It’s not a bike I can sneak around town on. People hear those Toomey pipes, and with the bike’s striking look, folks seem very intrigued by it. When waiting at a light it’s not uncommon for the person in the car next to me to roll down the window and ask me what kind of bike it is. These brief stoplight conversations usually end with, ‘Wow, cool!’”

“Here’s my favorite memory of the bike. Andy took me over to Jones Island (light traffic) so I could get used to the thing. After several trips around, we stopped for a break and Andy asked me, “Did you come onto the pipe?” Now, I’ve been around bikes and garages all my life, and I had no idea what he meant. It’s a strange question, one that can be taken many ways, even if asked by one’s own husband! Andy saw the puzzled look on my face and explained. I told him wasn’t really sure. In my next practice ride, I discovered I hadn’t yet hit the powerband, cause on that bike, YOU DEFINITELY KNOW WHEN YOU HIT IT! I fell in love with that bike right then and there. I guess coming onto the pipe will do that to a person.

“I really am one lucky girl!”

[Thanks to Mitch Boehm. Get your subscription to Moto Retro Illustrated here.]

Yamaha RD400 custom

  • tdc

    but suuuuper rad bike!! except… to use the side stand does she have to carry the little brick thing with her everywhere she gos?

  • Cool bike. Great story.

  • Darmah Bum

    Nicely sorted – well done – great story too. (makes me want to bust out my Sawzall)

  • Griffin

    I remember reading this article in a magazine with both my girlfriend and I drooling over this bike. It is still an awesome story about what is a kick-ass bike.

  • Two beauties there – both in black and blue. Very classy!

  • Not sure about the exhaust/pipes, and dislike the seat, but anyway it’s a nice bike.

    Black frame and forks maybe would be nicer.

  • Lew


  • el vencejo

    Another clean USEABLE machine, not so common to see 2-strokes customised.
    Great! Show us more and stay away from show-only bikes!

  • PeteP

    I’ve seen pictures of that bike before. What a great build!

    Hmmm, I’ve got a set of DG heads sitting around, and a pile of old race parts…..

  • Thats a great creation . I am fairly sure the tank is from a Yamaha RD200a ( drum brake model ) from 75/76
    Thanks for a great website

  • econobiker

    Yamaha cycles are so modular in parts sharing across the years. Per the tank- I am betting maybe from a Virago Route 66 250cc…

  • rob

    i like the h.i.d. headlamp enclosures…any clue who makes them?

  • mister dust

    arrrrghhhhh ……… remenber remenber four years with this machin, what’s fun ;;;;

  • PeteP

    Tank is from Yamaha Radian.(YX600?)

  • I’ve seen this in person, Very nicely done; love the fact that it’s a rider and not just all bling!

  • That bike just looks like loads of fun. It’s inviting me to jump on and start thrashing. I love it and am seriously considering an attempt at it for my next project bike. Nice.

  • i must forget the day i sold mine………

  • Oleg

    Hi there, is any info about it’s weight?

  • Sweet! It’s great when a simple build turns into something bigger. And look at the result. Custom motorcycles rule.

  • Warren Smith

    This one really hits home. After my race-bashed RD400F was retired (Northeast region, WERA and CCS), my talented machinist buddy (aka “Eyeball Engineering”) and me decided to upgrade the RD with, you guessed it, an RZ front fork and tree, and, RZ swing arm. Like you experienced, the front was almost a bolt in. We welded tabs on the swingarm to fit twin shocks. We had already re-positioned the foot pegs and mounted clubmans for racing. The roller was virtually ready to go when the ‘life got in the way” thing happened again. Sold the bike plus two other RD frame/motor rollers and a shed load of parts for $1000 in ’95. Kicking myself now that I see what real builders and a little elbow grease can accomplish! Currently own a appropriate old man’s Bandit 1200s but will hopefully add a little back-road blaster to the stable before I kick. Well done Mark and Lindsay!

  • Warren Smith

    Oops! Andy & Lindsay!

  • Jjstrods

    Very cool. I had a 77 RD 400 when I was 16. I had to hide it in my friends barn as my parents wouldn’t let us kids have anything dangerous, ie. fireworks, bb guns minibikes, trampoline etc. I never registered it, insured it or got my license. I just did mad midnight rides after quietly pushing out of my friends barn. I bought it for $600, two car speakers, a 22 ruger rifle, and some contraband. I eventually sold it to a friend from college who paid me 3 years later. I loved that psycho bike. I did wheelies every time I rode it by accident. I want another. P.S. great bike and beautiful girl. With looks like that I would guess that what Lyndsy wants Lyndsy gets. Thanks for sharing.

  • Fantastic! I would love to build a custom bike for my wife too. We think about building up an older Ducati Monster.