DUNCAN RACING: HONDA SPECIAL-EDITION 300R

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Without the Honda 250R, high-performance quads would not be where they are today. In 1986, the 250 two-stroke engine set a new standard for handling duncan racing and performance in sport quads. A good, stock 250R can still do more than most quad riders ever ask.

Duncan Racing International (DRI), which has won national championships with 250Rs, was so excited to ask how much DRI could add to a 1988 Honda 250R stock-frame, they went all out and made an incredible 300R!

Working with parts that are 30 years old is one of the challenges in modernising a 30-year-old machine. Duncan Racing solved this problem years ago by creating the PC 2000 cylinder kits for the 250R. The kit’s heart is a pre-ported, power-valve equipped cylinder. It replaces the stock Honda part. This project used the 305cc version because of its quick response and wide power delivery. For riders who desire more power and torque, there are 275cc or 340cc versions. This kit includes a precision-matched piston to the nikasil engine, a billet head, and an interchangeable dome.

The PC 2000 engine complete kit includes the cylinder as well as all related parts. Because the larger, port-engineered cylinder flows much better than stock, intake and exhaust upgrades were designed to maximize power with the best power curve. K&N air filter, prejetted Keihin PWK or Keihin PJ carburetor and Pyramid Reed valve are some of the intake side modifications. The exhaust side features a Paul Turner pipe, and a Fat Boy 2 silencer. DRI replaced the crankshaft with a Hinson/DRI clutch to make the engine reliable.

Although the Honda 250R’s basic geometry and chassis design were perfect, it was still a machine that could be used for trail riding. It also had shocks that were quite basic in comparison to modern racing components. Duncan Racing provided a long-travel, motocross-level suspension for this Honda using Roll Design Lobo IIA-arms and fully adjustable Elka Stage 5shocks front and back. The Honda’s national championship-winning suspension is now completely up-to-date, offering performance and tuneability that exceeds today’s top production quads. GPR steering stabilizers and Roll Design steering stems give riders extra control and comfort, which is especially important for a race-tuned machine with high horsepower. Laeger’s RPM axle and swingarm +1 keep the machine steady at speed, and prevent unwanted wheelies.

Any 250R can be thrilling, but riding one that is prepared like a race-car champion is something else. The race engine starts easily and settles into a relaxed idle. It revs quickly and responds with such precision that it makes duncan racing modern four-strokes feel a little slow compared to the perfectly tuned two-stroke. Although the 300’s power is vast, it still requires a more alert riding style that a four-stroke. A downshift or a quick touch of the clutch will relight the engine’s rocket-like thrust if you are under its true power. It is extremely fast. The engine will accelerate and want to upshift as fast as the rider can feed it.