Scary Fun: Yamaha RD400 Café Racer

Scary Fun: Yamaha RD400 Café Racer

Two-Stroke Smoker from Hawai’i’s Speedychoppy Builds… 

In 1976, the Yamaha RD400 appeared as the successor to the RD350, which had become a legend in its own time. Instead of simply overboring the 350, Yamaha created an entirely new machine. The RD400 had a longer stroke, new crankcases, a rubber-mounted engine, different wheels and brakes, and more. Yamaha even moved the engine forward in the frame to curb the RD’s tendency to wheelie — fortunately, they failed!

In stock trim, the new RD boasted 40 bhp and a top speed of 106 mph — though those numbers were just the tip of the iceberg. Soon the RD400 was smoking round streets and circuits here and abroad, earning its reputation as a worthy successor to the RD legend:

“Weighing in at 160 kilos, the 398cc RD400 became the ultimate racing-derived, two-stroke street racer. While Yamaha’s contracted racers enjoyed massive success in GPs, the firm’s road customers were having just as much fun haring round the streets…” –Visordown

Recently, we got in touch with Tyrone Montayre of Hawai’i’s Speedchoppy Builds — an O’ahu native who grew up around motorsports, racing motocross, autocross, and import drags before becoming a mechanic at an Audi, Harley, Kawasaki dealership on Maui. That’s when he got his first street bike, an ’03 R6:

“Picked it up quick and learned how to drag a knee riding up in Haleakala Volcano. Maui has really nice long roads compared to O’ahu, but no road course track.”

Once he got bored racing up the volcano, he shipped the bike to O’ahu and began flying back and forth to race at the local track — alas, that track is no more:

“Moved back to O’ahu in 2003 and raced till the track closed in 2006.”

Today, Tyrone is the land steward for Protect & Preserve Hawai’i, and still keeps his hand in a couple days per week at the local Land Rover / Jaguar dealership.

The idea for this RD400 build came while he was working on Maui, when one of the dealership’s motorcycle techs (Jason) kept talking up two-strokes, telling him a properly set up RD could give his modern R6 a run for the money.

“One day his friends rode in on two newly restored dirt tracker style RD’s built by Moto Carrera. With that droning two-stroke twin cylinder sound and smell I was hooked. I obsessed with building one…”

Tyrone picked up a ’78 RD400 off eBay and got to work in his 10’ x 18’ converted storage room, looking to build a period-correct street racer with modern touches. He gives us the full specs below, but highlights include repro Super Webco heads, Stage 2 porting courtesy of land speed record holder Ed Erlenbach, forged Wossner pistons, rebuilt crank, undercut transmission, YZ85 VForce reeds, Pro Design intakes, larger Mikuni VM30 carbs, and Fukui Racing titanium chambers from Japan — can you say wheelie?

The bike is rolling on wider Daytona wheels with Brembo brakes, rear Öhlins piggyback shocks, and front forks rebuilt with Öhlins valving. Ian Halcott of fabricated the seat and oil tank, while Hannibal A Williams Jr. of Cycledelic Custom Paint handled the paint and hand-painted graphics.

The bike looks a treat, and goes even better:

“Scary fun when the powerband hits and lifts the front through 3rd gear. Flicks into turns very easily making it a joy to ride. The vibrations, smell, and sounds of vintage two-strokes are like no other, and just brings a smile to my face.”

Below, we talk to Tyrone for the full story on the build, with photos courtesy of Francis Joy (@zenjin808).

Yamaha RD400 Café Racer: Builder Interview

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

Born and raised in Makakilo City on the island of O’ahu, Hawai’i, a few miles from where the race track was until it closed in 2006. Currently no track on O’ahu. Grew up around motorsports with family and friends racing cars and motorcycles. First bike was an ’82 RM80 when I was 12.

Eventually started racing MX at the local club racing track off and on. Got into cars and import scene in the 90’s in high school doing drags and autocross. Had an aptitude for mechanics and loved competitive motorsports racing. Became an auto mechanic working at various independent shops till ending up working for a Land Rover, Porsche, Audi dealership.

In 2002 I took an offer to move and work on the island of Maui at a new Audi, Harley, Kawasaki dealership. Parents always told me because of their worries that I could never have a street motorcycle as long as I lived in the house. Now being out of the house, I bought my first street bike (2003 Yamaha R6). Picked it up quick and learned how to drag a knee riding up in Haleakala Volcano. Maui has really nice long roads compared to O’ahu, but no road course track.

I got bored racing up the volcano. I admitted owning the bike to my parents — they accepted me having a street bike and agreed to let me store the bike at their place, so I shipped it back to O’ahu and started flying back and forth to race the local club racing road course. Moved back to O’ahu in 2003 and raced till the track closed in 2006.

I’ve always had some kind of project, usually building cars and bikes. In 2018 stumbled across some preservation land at a tax auction and decided to be its land steward in 2019 — started a nonprofit, Protect & Preserve Hawai’i.

We offer education opportunities, access for the community, and forest watershed restoration.
I realized the earth needed fixing more that customers’ cars, so in October 2022 I shifted full time to the nonprofit and work just two days at the Land Rover and Jag dealership as a diagnostic tech till I can secure sustainable funding.

My workshop is an old 10’ x 18’ converted storage room.

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

1978 Yamaha RD400, eBay shipped from Arizona.

• Why was this bike built?

Personal.

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

Minimalistic, period-correct retro w/ modern influence. TZ250, Yamaha R6 shark nose lights. For the year that I worked in Maui at the Audi/Harley/Kawi dealership there was a motorcycle tech (Jason) who could not stop talking up about how awesome RD’s were. He would say that a properly set up RD would be able to compete with my modern R6. One day his friends rode in on two newly restored dirt tracker style RD’s built by Moto Carrera. With that droning two-stroke twin cylinder sound and smell I was hooked. I obsessed with building one off and on ever since till I found one on eBay in 2013.

• What custom work was done to the bike?

Seat and custom oil tank by Ian Halcott previously of Twinline moto and .

Engine has a Stage 2 Porting by land speed record holder Ed Erlenbach, as well as machining cylinders to fit YZ85 VForce reeds mating to Pro Design intakes to larger Mikuni VM30 carbs. He also rebuilt the crank and transmission, which was sent out to be undercut at R&D Motorsports. I assembled the engine with new forged Wossner pistons.

Also, I installed reproduction Super Webco cylinder heads. Those and DG heads in that era “were tits” as they say. Then in the past decade both were reproduced. I really wanted the Super Webcos. They were on my wishlist and didn’t realize how limited they really were till Economy Cycle said they sold out. I hunted down the source and thanks to Ralph Ponce of @super_webco he was nice enough to sell me a set from his personal stash.

Mike Kamemoto of Infinite Machine Works was responsible for machining billet caliper brackets to fit larger discs and Brembo calipers, axle adapters and other various machining needs. Yamaha R6 triple clamps and front forks rebuilt with Öhlins valving to complement the rear Öhlins piggyback shocks.

Hannibal A Williams Jr. of Cycledelic Custom Paint hand painted the graphics and paint.

Detabbed, powdercoated, moving parts Cerakoted, Vintage Smoke rear sets, Fukui Racing Ti chambers from Japan imported by Samu Rider Japan. Wider and lighter Yamaha Daytona wheels. RD350 engine covers modded to fit. (Just because RD400’s are plain to me.)

• Any idea of horsepower / weight numbers?

332 lbs, no idea on power.

• Can you tell us what it’s like to ride?

Scary fun when the powerband hits and lifts the front through 3rd gear. Flicks into turns very easily making it a joy to ride. The vibrations, smell, and sounds of vintage two-strokes are like no other, and just brings a smile to my face.

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

All of my builds, I always enjoy the journey over the destination. Dreaming it, manifesting, then materializing it. One thing that I had fun with was researching brake rotors with the same bolt pattern and correct offset through multiple databases to come up with what I did. The other would assembling the engine and transmission. It was a first for me. It was like an automotive standard transmission and engine combined!

• Is there anyone you’d like to thank?

My good friend Elmer Rivera who did all the tank welding and body prep work, Layden Paulino for helping me source out parts, Ian Halcott, Ed Erlenbach, Hannibal A Williams Jr. (@808painter1) of Cycledelic Custom Paint, Mike Kamemoto of Infinite Machine Works, the crew at Montgomery Powersports, Ted’s Automotive Machine Shop, Ralph Ponce of @super_webco, and John Rodenhiser of economycycle.com. Photo credit: Francis Joy (@zenjin808).

Follow the Builder

Web: protectpreservehi.org
Instagram: @speedchoppy_builds | @protectandpreservehawaii

This content was originally published here.

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