Andy Underhill’s resto-modded RD350, boasting YPVS power…
Introduced in 1980, the Yamaha RD350LC was the next evolution in two-stroke street performance. Though it succeeded the larger displacement air-cooled RD400, the LC — aka the “Elsie” or “4L0” — boasted a smaller, liquid-cooled 347cc engine whose bore and stroke matched that of the older RD350 (64 x 54mm) but made 46-49 horsepower in factory trim. At the same time, it managed to comply with the ever-tightening emissions standards that were threatening to squeeze the street-going two-stroke into extinction.
In 1983, the final evolution of the RD series arrived, the Yamaha RD350YPVS — also known as the RZ350 (North America) or the RD350LC II. It was outfitted with Yamaha’s YPVS (Yamaha Power Valve System), which used a rudimentary computer to vary exhaust port height/timing, increasing low RPM torque while maintaining high RPM horsepower. Introduced at Germany’s Cologne Motorcycle Show, the YPVS was hailed as the hottest street-legal production two-stroke in history:
“The factory claim the ’83 RD unveiled in West Germany is the nearest thing to a road going racer ever produced.” —Motorcycle News, 1982
Over the years, garage builders began to create “hybrids” — restomod-style RD’s retrofitted with newer engines from the series and upgraded suspension, brakes, wheels, and more. The bike you see here is one such build, a Yamaha RD350LC hybrid from Andy Underhill of the UK, who’s owned the bike since ’99!
“This was bought as a cheap work hack but evolved into an obsession which 20 years later, you see here… Concept behind the design was to build my vision of a modern up-to-date LC, whilst keeping the retro style of the original 80’s icon.”
Working out of a small 12×10 wooden shed, Andy has created one of the most baddest, most stunning two-stroke street machines we’ve ever seen. It’s a standard RD350LC frame, braced and powder-coated, with a built YPVS engine that boasts Wiseco pistons, a stroker crank, Pro Design Coolheads, Zeeltronic ignition, aluminum radiator, GP-style exhaust, and much more.
Suspension, brakes, and wheels were also given the treatment. The bike is now running a set of RGV250 forks and brakes, Metmachex custom swingarm, MT-09 rear shock, wire wheels, and more. Then there’s the paint — a double-sided “zipper” scheme that’s different on each side, making Andy’s RD like two bikes in one.
It’s a bike you could drool over all day, but it begs to be ridden hard:
“The bike is an absolute hoot to ride. Second and third gear wheelies are no problem. Always have a grin when riding her.”
Below, we talk to Andy for the full details on the build.
Yamaha RD350LC/YPVS: Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
My name is Andy Underhill, 54, but riding bikes since I was 16. Started off on Suzuki TS50ER before progressing to a Honda CB125 twin. Once I’d passed my test, my first big bike was a 1983 Yamaha RD350YPVS. Several more strokers came and went over a few years before moving onto a diesel (4-stroke) FZ750.
Since then I’ve had several big diesels (ZX9, TL1000s, GSX-R1000, Aprilia Tuono V2) but have always had 2-strokes in the stable. I’ve owned my current 350LC since 1999. My workshop is a small 12′ x 10′ wooden shed.
• What’s the make, model, and year of the donor bike?
Current bike is a Yamaha RD350LC hybrid.
• Why was this bike built?
This was bought as a cheap work hack but evolved into an obsession which 20 years later, you see here.
• What was the design concept and what influenced the build?
Concept behind the design was to build my vision of a modern up-to-date LC, whilst keeping the retro style of the original 80’s icon.
• What custom work was done to the bike?
Standard 4L0 350LC frame braced and powder-coated.
MT09 rear shock
Metmachex custom swingarm
RGV250 forks and brake calipers
RVF front discs
Wire spoked wheels front and rear
GT750 front hub
TDR250 rear hub
Bridgestone BT090 tyres
YPVS engine: 4mm stroked crank, Wiseco pistons, Pro-design coolhead, Zeeltronic ignition, 31k carbs with ram-air filters.
Ally radiator and one-off GP style exhausts.
Digital clocks, Pazzo levers, Tyga rearsets from an RGV250.
Std 4L0 LC bodywork painted in the half n half “zipper” paintscheme.
• Can you tell us what it’s like to ride this bike?
The bike is an absolute hoot to ride. Second and third gear wheelies are no problem. Always have a grin when riding her.
• Was there anything done during this build that you are particularly proud of?
Paintwork is the part the everyone comments on, then the wheels and exhausts.
Sweet! These RDs make awesome resto-mods. I always admired this first version of the 2-stroke, liquid cooled, twin. We never had this ’83 RD350 in the USA. The ’84 &’85 RZ had different bodywork etc. All the liquid cooled Yamaha 2 strokes are ultra-cool and now, classic.
I had a 74 RD350 WITH CHAMBERS on it and it would do 100mph easy with me and my gf on it!!! Super fun 😄 bike