PROJECT ATV: HONDA TRX250R

Duncan Racing replica...

One crazy ’88 By the staff of Dirt Wheels

The Honda’s upgraded engine puts out a lot more power that is still controllable. Sunoco STD race fuel is used in the stock fuel tank. Josh Row put on a show for the camera on this build.

PROJECT ATV: HONDA TRX250R

This exceptional Duncan Racing 1998 Honda TRX250R two-stroke build is not restoration in the classic sense. Restoration is a faithful return of the machine to the exact condition it was in when it hit the showroom floor.

This one has been returned to better-than-new condition, and it has more stock and original parts than most of the TRX250R builds we see. It has also been upgraded with seriously trick aftermarket parts—the best that can still be found. At the same time, it holds onto the cultist roots of what a true 250R should be.

The Duncan brothers stripped this Honda to its bare bones, strengthened the frame, and rebuilt this beauty to a state well beyond its original glory. When we drove up to the Duncan Racing International headquarters, our jaws dropped; we were gazing upon one crazy ‘88!

Works Connection makes a very popular and comfortable clutch perch and lever setup. A Motion Pro clutch cable replaced the worn-out stock one.
Duncan Racing relies on GPR’s V1 steering stabilizer to help riders control the TRX250R. It has a dial that controls how stiff or loose the stabilizer can be.
Duncan Racing found a stock set of Honda TRX250R tires and mounted them to DWT rolled-lip chrome rims for this build.

PROJECT ATV: HONDA TRX250R

SMOKIN’ PIPE

Duncan Racing (DR) builds highly specialized and personalized machines for their customers that are fully prepared for racing (it’s in their name), but it also offers kits that increase power but are still manageable enough that weekend riders can tame them.

DR installed their PC 2000 275cc Midrange engine kit to start the build. This kit utilizes a 275cc cylinder, which is the largest bore you can run without having to bore the engine cases. The PC 2000 cylinder also comes in 305cc, 340cc, and 344cc versions. If you really want to go full-bore on your build, DR offers a custom-built 360cc setup.

This PC 2000 275cc kit comes with the PC 2000 power-valve cylinder, a billet cylinder head, piston, piston rings, and more. Other additions to this build include a DR dual-O-ring exhaust flange, a Pyramid reed valve, and a pre-jetted Keihin 39mm PWK carburetor.

Duncan rebuilt the original Honda crankshaft, topped the cylinder head with an NGK BR9EIX spark plug, and aimed the exhaust gases through a Paul Turner Eliminator pipe with a Fat Boy 2 silencer attached to it. The stock airbox was reused on this build, but it now contains a K&N air filter diligently filtering dirt from the air so the TRX can breathe.

Of course, it didn’t stop there. DR spent hours polishing the engine to shine brilliantly in the sun! Before the engine was buttoned up, though, Duncan bolted in a Ricky Stator stator.

Roll Design A-arms and Elka Stage 5 shocks are a perfect combination for a smooth long-travel setup. The Elka shocks have a triple-rate spring setup.

 

 

Duncan rebuilt the entire engine, adding a large number of power parts. Their PC 200, power-valve, 275cc cylinder; trued crankshaft; Pyramid reed valve; and more were added to the two-stroke.

PROJECT ATV: HONDA TRX250R

History is cool, but there was no sense putting vintage suspension on the gusseted stock frame. Instead, a Roll Design A-arm kit was mated to Elka Stage 5 shocks. Roll is the Elka specialist, so the suspension is perfectly tuned for any riding conditions that the owner specifies.

At the end of the Roll A-arms are OEM spindles and hubs. Roll Design was the source for the steering stem and anti-vibe bar clamp as well.

To make the front suspension feel even better, a GPR stabilizer was mounted to allow the rider to hold the grips with hands relaxed. The GPR doesn’t allow the handlebar to jerk around in the bumps, and you can adjust how much control you want. And that wasn’t all. A Fasst Flex bar further isolates the rider from the terrain abuse.

A stock swingarm and linkage were retained, but an RPM Dominator II axle is speared through the OEM carrier. That stock swingarm was mated with a dialed-in Elka Stage 5 shock. Sunstar sprockets with an RK Excel chain get the power reliably to the rear axle.

The point here is to have a quad that looks as good as you remember, and rides even better than you remember!

The Roll Design and Elka suspension combo far outperform the Honda’s stock setup. The ride is plush and smooth on many types of terrain.

PROJECT ATV: HONDA TRX250R

MORE GOODIES

It makes no sense to rebuild the whole bike, boost the performance and suspension, and use 32-year-old brake lines. Duncan Crown Series brake lines and clamps make sure that commands sent from the master cylinders actually reach the calipers. For a great look and seated pant traction, a Zip seat cover does the job. For riding, while standing, Roll Design pegs have some serious teeth to keep your boots in place.

Powder1 powder coating and Pacific Plating went beyond duty to make this machine a stunner. Finishing up the look of the machine are Maier plastic body parts encased in Duncan Racing graphics. The DWT wheels did not need polishing. They are available polished with a rolled bead.

While they may suit the look of the machine, the OEM Dunlop Honda tires were located and mounted. Those Dunlops are great overall tires that perform well.

A Paul Turner Eliminator (triple-plated chrome pipe) is paired with Duncan Racing’s Fat Boy 2 silencer. This setup sounds great and adds to the engine performance of the PC 2000 Midrange engine kit.

GETTING IT DONE

Completed, this 1988 high-performance two-stroke weighs in at a svelte 350 pounds! Even though the TRX250R is 32 years old, it doesn’t feel its age when it is in good shape.

That goes double or even triple for this masterpiece from Duncan Racing. Owners who are motivated to attain this level of perfection are generally motivated at least a little by memories of riding or even seeing the TRX when it was new or near new.

Not many motorcycle guys would choose a 1988 bike to build. For sure no mountain biker wants to restore and ride a 1988 bicycle as his daily ride. Too many times, the memory ends up being so much better than reality.

Honda’s TRX250R seems to have dodged that bullet. When you ride a TRX250R, and especially the 275cc version with modernized suspension, it doesn’t feel vintage. It feels like a lightweight weapon. It turns, jumps, and handles the rough just like a pro quad should. And, it looks fantastic doing it.

An RK Excel Premium ATV O-ring chain rides on a set of Sunstar sprockets. DR installed an RPM Dominator II axle that is wider than stock. The Honda’s OEM swingarm and linkage remain on the ATV.
Roll Design footpegs have sharp teeth and a kick-up at the end of the peg that offers great foot traction.
A Zip seat cover offers more grip than the OEM one, along with some added style.

PROJECT ATV: HONDA TRX250R

PARTS LIST:

DOUGLAS WHEEL & TIRE: www.dwtracing.com, (800) 722-3746

Polished, rolled bead front wheels $74.95 

Polished, rolled bead rear wheels $85.95 ea.

DUNCAN RACING: www.duncanracing.com, (619) 258-6309

PC 2000 275cc Midrange engine kit $2995.00

Rebuilt OEM crankshaft $349

Dual O-ring exhaust flange $89.95

Pyramid reed valve $199

Keihin 39mm PWK carburetor $259

DRI clutch kit $199

Crown Series steel-braided front brake lines $119

Crown Series steel-braided rear brake line $39.95

Billet brake line holders $39.95 each set frame strip, gusset & reinforced N/A

Chrome front bumper $229

Chrome grab bar $54.95

Graphics kit $149

Parking brake block-off plate $15

Chainguard $39.95

Paul Turner Eliminator triple-plated chrome pipe & DR Fat Boy 2 silencer $599

ELKA SUSPENSION: (800) 557-0552, www.us.elkasuspension.com

Stage 5 front shocks $1,809.99

Stage 5 rear shock $1,195

FASST CO.: (877) 306-1801, www.fasstco.com

Flexx handlebar $359.99

Bar pad cover $10

GPR STABILIZER: (619) 661-0101, www.gprstabilizer.com

V1 ATV damper kit $549

HINSON RACING: (909) 946-2942, www.hinsonracing.com

Billet clutch basket $250

MAIER POWERSPORTS: (800) 336-2437, www.maier-mfg.com

Plastics $766.10

MAXIMA RACING OILS: (800) 345-8761, www.maximausa.com

927 Premix oil $19.95 per Liter MTL Endurance trans fluid $9.95 per liter Chain wax $11.50 per can

550 brake fluid $6.95 per bottle

MOTION PRO: (650) 594-9600, www.motionpro.com

Clutch cable $8.99

PACIFIC PLATING: (619) 295-0496, www.pacificplatingsd.com

Plating of: shifter, motor mounts, kick starter, rear brake pedal Price varies

POWDER 1: (619) 588-9200, www.powder1.com

Powdercoating: Price varies

RICKY STATOR: (760) 787-0094, www.rickystator.com

Hi output stator $229

RK EXCEL: (760) 732-3161, www.rkexcelamerica.com

Premium ATV O-ring chain $99

ROLL DESIGN: (760) 731-5920, www.rolldesign.com

Lobo II Desert front suspension kit $3395

Anti-vibe steering stem $299

Anti-vibe handlebar clamp $99.95

Footpegs $239

RPM: (928) 771-9363, www.team-rpm.com

Dominator II axle w/ OEM carrier $499

SUNSTAR: (937) 704-1462, www.sunstar-braking.com

Powerdrive 15-tooth countershaft sprocket $26.95

Rear 38-tooth steel sprocket $45

WORKS CONNECTION: (530) 642-9488, www.worksconnection.com

Clutch perch assembly $129

ZIP: www.zipracing.biz

DR Edition Pro Top seat cover $199

Click the link below to see another test of Duncan Racing quads.

https://dirtwheelsmag.com/duncan-racing-warrior-vs-duncan-racing-honda-300ex/

To subscribe to Dirt Wheels Magazine in print or digital form click here https://hi-torque.com/product/dirtwheels.

Duncan RacingDuncan Racing HondaDuncan Racing reviewHonda Fourtrax 250RModified Honda ATVs