As soon as a teenage dream machine, this RD350LC returns as a nostalgic hybrid with sharper dealing with, a much bigger engine and a basic Yamaha livery.
If you happen to had a motorcycle within the shed and a tv within the mid-Nineteen Seventies, there’s a superb probability you had been dying to get your arms on a liquid-cooled Yamaha two-stroke. Yami’s new TZ liquid highway racers had been shaping the subsequent era of two-stroke efficiency on the tracks, however street-goers needed to accept air-cooled RD350s and 400s, which should have felt positively antiquated as compared. However pace freaks of the period wouldn’t have to attend for much longer.
Yamaha launched the RD350LC in 1980 to keen public reception, and whereas the manufacturing mannequin was extra of an RD with an impeller than a TZ with indicators, it nonetheless represented a quantum leap in efficiency if phrases like port and powerband had been your widespread vernacular. The place most two-strokes had been watered-down to work nicely throughout the rev vary, the 350LC’s exhaust, port timing and carburetors had been optimised above 7,500 rpm, and the rear mono-shock cleaned up the dealing with habits of the previous twin-shockers.
Whereas the RD350LC didn’t come to the States, different markets ate up Yamaha’s new liquid and begged for extra, particularly in Europe. The outcome was predictable: a era of riders fell in love with the LC—and an enormous variety of them ultimately stuffed these bikes into hedges, ditches or lampposts. It’s one motive clear survivors are such a uncommon sight as we speak.
Patrick Lyall remembers that period vividly. He got here of age simply because the LC exploded onto the scene and owned a crimson 250 at 17 within the ‘Bounty Bar’ shade scheme. Like many riders who grew up on two-strokes, he ultimately moved on to larger four-stroke equipment. However the LC has a manner of sticking in your reminiscence; when you’ve skilled that frantic powerband, it sticks with you.
The spark reignited through the COVID lockdowns. With time on his arms, Patrick began shopping for drained two-stroke initiatives on-line and bringing them again to life—machines like a Montesa Enduro and a Suzuki TS125ER. Across the similar time, he and a pal rode right down to the Ace Cafe for the annual 2-Stroke Sunday: Blue Haze Day gathering. Among the many clouds of smoke had been a number of RD ‘hybrids’: basic LC frames upgraded with fashionable suspension, brakes and wheels. The idea made good sense. You didn’t want an entire donor bike to construct one thing particular, and newer parts are simpler to supply—to not point out much better in terms of braking and dealing with. The ultimate push got here from an article in Sensible Sportsbikes Journal overlaying an RD250LC hybrid constructed by Wayne Leach, which impressed a lot of Patrick’s selections through the construct course of.
The true work began when Patrick purchased an LC body from a pal who restores these bikes. From there, he teamed up with Nigel Kimber at NK Racing to map out the chassis. Many RD hybrids run a Suzuki RGV swingarm, however Patrick felt that setup stretched the bike’s proportions too far. As an alternative, they opted for a swingarm from the Honda NC29, paired with forks from a Kawasaki ZX-6R. Kimber dealt with the machining and fabrication to make all of it work, producing a chassis that retains the LC’s compact stance whereas dramatically sharpening the way in which it rides.
Aprilia RS125 wheels end the rolling inventory, whereas Kimber additionally fabricated new rearsets and machined the mandatory parts to combine all the pieces cleanly into the unique body. The tip outcome nonetheless appears unmistakably like an LC—however tighter, decrease and way more purposeful than Yamaha ever supposed in 1980.
The engine got here from Italy through eBay earlier than being rebuilt by Patrick’s pal Stephen “Rocket” Roberts. The cylinders had been despatched to Ron Phillips at Faron Engineering for porting, resleeving and contemporary pistons, bumping capability as much as 375 cc. A pair of 32 mm Mikuni flatslide carbs sourced from the US feed the motor, whereas hand-built growth chambers from Jim Lomas Exhausts present the soundtrack. The pipes are made out of delicate metal—favored for efficiency—even when it means they require a bit extra care. After getting uninterested in sharpening them continuously, Patrick ultimately lacquered the pipes to maintain the rust at bay.
Like many long-term builds, the mission hit just a few painful bumps alongside the way in which. At one level, the freshly rebuilt engine, cylinders and modified swingarm had been stolen from the again of Patrick’s automobile—forcing him to return to Kimber and Phillips and ask them to recreate the work. Given the ready lists each specialists usually have, it was the sort of setback that would kill a mission. Fortuitously, each stepped up and helped get the construct again on observe.
Particulars all through the bike present the identical degree of care. The seat was formed and stitched by Dave the Trimmer and embossed with Kenny Roberts’ signature to match the basic Yamaha race-inspired paint scheme. The electrics had been dealt with by Andy Woolrich of Electro34, together with a bespoke wiring loom. Trendy digital gauges from Smiths had been tailored to suit inside the unique LC housing, with customized dial art work created by Patrick’s son Matthew. Eager eyes will spot the trick hydraulic clutch setup, one other piece of Kimber’s handywork that brings the RD’s efficiency into the trendy period.
Closing tuning occurred on the dyno at RHR Bikes. In full race trim, the engine produced round 80 horsepower—severe output for a motorcycle this mild—however Patrick opted for a barely softer highway tune that introduced the determine right down to a still-lively 64 bhp whereas including stronger mid-range. Even so, the motor spins to 13,000 rpm, which is awkward when your tach solely goes to 10.
A race-spec TZ crankshaft and upgraded ignition are already lined up for the subsequent stage of the construct to soundly help these revs. As Patrick jokes, he could find yourself writing the lacking numbers onto the tach himself.
The completed machine is strictly what an excellent hybrid ought to be. It captures the look, angle and nostalgia of the unique RD350LC—however rides like one thing far sharper. To anybody who remembers the period, it’s a time machine again to the golden age of two-strokes… simply with higher brakes, higher suspension and so much much less probability of ending up in a hedge.
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