This super-slick Yamaha RD350 is Peter’s latest production. What makes it even more amazing—given that even high-end pro builders often farm out tricky jobs—is that Peter handled every aspect of the build with his own hands.
The RD350 cost around AU$1500 (around US$1,100) all up. And about $500 of that was the high-performance PVL ignition—a component that cannot be built without specialist equipment.
Starting out, Peter cut the original side rails, the top bar and the rear loop from the frame—and pulled the head angle back to 25 degrees. He then welded in the top bar and rear loop from a Yamaha DT2, allowing him to fit a conventional Knight tank. The tailpiece is an old XR750 copy that Peter found on eBay.
To get the desired amount of trail for the decreased rake, Peter has installed an old set of MX Yamaha triples with a favorable offset. Then he built up a 19-inch front wheel with an MX Yamaha conical hub: “We have to run a front brake over here.”
The forks are from a Kawasaki 250, cut down and rethreaded for the fork caps, with a lug welded on for the brake plate stop. The rear wheel is from a KLX250: “A nice light hub, with an effective brake.”
Luckily the 347cc air-cooled, two-stroke parallel twin was in surprisingly good condition, with quite low miles. “All I did was replace the seals, bearings and gaskets, and fitted new rings after honing the bores.”
Peter did machine the cylinder heads though, to set up the squish and compression, and fitted spacers in front of the reed valves to un-shroud the boost ports. Otherwise the engine is stock except for the PVL ignition.
“That enabled me to get rid of the ignition, alternator, rectifier and battery,” he says. “I also cut down the alternator cover, which narrowed the left hand side of the motor considerably.”
The carburetors are stock, but re-jetted to suit the pipes and pod filters. “I designed and made the pipes for more mid-range than top end. I didn’t want a big hit when it came on power, and it works well. The bike is very quick, being considerably lighter than a stock RD350.” (Which, we should add, was no slouch and known as a giant killer in its day.)
It’s a classic example of an extremely talented ‘amateur’ whose skills put some so-called pro builders to shame. Peter did everything in his own workshop except for the seat cover—including the painting, powder coating, plating, polishing, machining, welding and sticker cutting.
And the ‘RDT350’ name? “I make up model identifiers for the specials based on the origins of the major components,” he explains. “On this one the top bar, rear loop, triple trees and front wheel are from a Yamaha DT250.
“And with it being a dirt tracker, I think it fits the bike perfectly.”
Images by Matthew Coppins-Skinner.