Project CRF256X: A Street-Legal DirtBike?

Jay Clark Enterprises takes an aging Honda CRF250X and repurposes it for street-legal dual sport use everywhere but in California…sort of.

Living in California is one of those great double-edged swords.

Californians enjoy great weather year-round, diverse culture and a tremendously varied landscape in which we can enjoy an assortment of outdoor pursuits. At the same time, California’s political climate is one that limits our choices when it comes to pursuing them.

Jay Clark Enterprises built this Honda CRF2506X to show how easy it really is to convert a bona fide dirtbike for dual sport use. Unfortunately, for Californians, emissions regulations prohibit such modification. Too bad, because the bike works great!
Jay Clark Enterprises built this Honda CRF2506X to show how easy it really is to convert a bona fide dirtbike for dual sport use. Unfortunately, for Californians, emissions regulations prohibit such modification. Too bad, because the bike works great!

That’s certainly the truth when it comes to enjoying off-road recreation, where the Air Resources Board, the regulatory agency that monitors air quality and imposes regulations in an attempt to curb air pollution have enacted strict policies to limit individuals from building or modifying vehicles that do not comply with those regulations for street use. That includes converting an off-road motorcycle for street use because it does not contain the correct emissions equipment.

However, since most of the U.S. does not have to follow those same regulations, we present to you a true alternative to factory-built Japanese or European dual-sport machines available in dealer showrooms. Jay Clark of Jay Clark Enterprises has the recipe down pat, and his Honda CRF256 X delivers the kind of performance and fun that can only come from a truly dirt-derived machine. We’ll concede that it won’t make for a great daily ride, but if you live in state where such a machine is allowed, and if only a few miles separate your front door from your favorite fire-road or single-track paradise, a bike like Clark’s is the hot ticket. Even better, if you have a are a resident of one of those states, you can get a plate for such a bike and be “legal” anywhere you ride in the U.S. Either way, the CRF256X, is a showcase of the aftermarket companies that Clark works with when building one of his custom creations.

“Most of us do work for a living and don’t have a trust fund, so we can’t go buy the latest street-legal dual sport out there,” Clark said. “In the Western states close to California, making your bike street legal is not too tough, and you do not have to deal with the Air Resources Board. So, to build this bike we went to our buddy’s house in Utah to build the bike there legally, since the bike would be used there 90 percent of the time to connect awesome trail to more awesome trail.”

The starting point for the CRF2506X project was a 2004 Honda CRF250R that was picked up for a paltry $1200.
The starting point for the CRF2506X project was a 2004 Honda CRF250R that was picked up for a paltry $1200.

Clark got the ball rolling by scoring a great deal on a Honda CRF250X that was in need of a rebuild.

“We picked it up for $1200 because the previous owners tried doing some of their own top end work and were not qualified to do so,” Clark said. “The bike was running but not correctly. They had overtightened the head bolts and stripped out two of the threads in the cases.  At that point we figured we would completely rebuild the engine since we planned to dual sport for years to come with this machine. Besides, the CRF250X has been basically the same bike since it came out in 2004, so we have plenty of experience with the machine and know that with just a little help we can make it run as well as a CRF250R.”

Since he was tearing the engine apart anyway, Clark started with Hot Rods, who supplied a complete crankshaft and main bearings. With bottom end repaired, he then added a Cylinder Works big bore cylinder kit that bumps the bore size 1mm, increasing engine displacement a few cubic centimeters more than the stocker, to 256cc. That’s a rather odd displacement figure, but Clark has an explanation for it.

“The first question we get on this move is, ‘Why only 1mm larger?’” Clark said. “The cases on the older 250Rs and all 250X models are very tight and require boring the cases for any larger big bore. We wanted to keep it simple so we went with just the small increase in displacement.

The key to pulling more power out of the engine really lies in proper airbox mods. The video below shows how that is done.
The key to pulling more power out of the engine really lies in proper airbox mods. The video below shows how that is done.

Clark also had Millennium Technologies rework the stock valve seats before handing the head to friend and local engine builder Jim Chamberlin.

“Jim has a lot of experience with the 2004 through 2008 CRF250s from when they were racing those bikes on the pro level,” Clark said. “We installed a Hot Cams Stage 1 camshaft but kept the stock style valve train and used the Xceldyne new X-2 line of valves and springs so all was fresh in the top end.”

Clark also added a complete FMF Racing exhaust system help the CRF256X breathe. However, he is quick to point out that all aftermarket parts in the project cannot live up to their potential with a stock CRF carburetor and airbox. Opening up the airbox and re-jetting the carburetor are a must to achieve the desired performance gains. The following videos show what steps Clark took to allow the CRF256X to breathe properly.

While working on the carburetor, Clark also removed the Hot Start cable from the bars and carb. This video shows how to do that.

The next step was a rebuild of the suspension, which was clearly set up too soft for the kind of riding Clark wanted to do. A phone call to Race Tech got Clark the parts and specs he needed to set the suspension up for the kind of riding Clark intended to do.

“At the same time we removed the stock odometer and more of a CRF250R setup,” Clark said.

The following video shows how it that was done.

Clark also opted for new lighting, so he fitted a Tusk lighting kit. This was actually one of the more involved steps in creating the CRF256X, as Clark says that it requires a lot of work to wire the kit but the following video gives an idea of how the Tusk kit is installed.

“It will take way longer than the 8-minute video, but it will only take 1-2 hours max if you take your time and solder all of the connections properly,” Clark said.

Since he wanted to ensure that the headlight was getting plenty of juice to make it as effective as possible, Clark also added a Trail Tech kit with a higher output stator.

To ensure that he had enough lumens for safe street use, Clark fitted the machine with a Tusk lighting kit.
To ensure that he had enough lumens for safe street use, Clark fitted the machine with a Tusk lighting kit.

Turning his attention to the cooling system, Clark sent the badly bent stock radiators to ICW to have them straightened, a cost-effective alternative to new radiators. Most of the other changes to the bike, he admits, are not necessary.

“Many of the, let’s say, ‘more bling’ parts to help it look good and not like a 12-year-old bike,” Clark said. “You don’t necessarily need parts like new plastic, a new seat cover, Works Connections perches, etc., but the stuff works well, and you can’t say it doesn’t look nice.”

Obviously, dual sport riding requires much taller gearing than motocross to balance out performance ion and off the road. Clark opted for a 13-tooth countershaft and a 49-tooth rear sprocket.

Once the bike was up and running, Clark said that he experimented with gearing a lot, ultimately settling on a 13-49 (3.76:1) final ratio, although he adds that riders who intend to do a little more street or road riding may want to drop to a 48-tooth rear sprocket.

All that was left was to head to the local Utah DMV to obtain a license plate.

“In Utah the process is very simple for the title,” Clark said. “You need to get a vehicle inspection from law enforcement or a Jiffy Lube-type place, and you take that in to the DMV and pay some very small fees after you wait in a very small line—all very un-California.”

And that’s that. Clark now has a legal dual sport motorcycle that meets all of his specific needs for enjoying riding in legal off-road riding areas around the country. And he should know. He built it himself.

Clark-CRF256X-Project-J-07-12-2016

2004 CRF250X Parts List

Cylinder Works                                www.cylinder-works.com      515-251-4070

1mm Big bore Cylinder Kit 365cc

Includes Forged Vertex Piston and Cometic Top-End gasket kit

 

Hot Cams                                           www.hotcamsinc.com            515-402-8200

Stage-one Camshaft

 

Hot Rods                                 www.hotrodsproducts.com          515-402-8100

Complete Bottom end kit

Includes complete crankshaft, main bearing seal kit and complete engine gasket kit.

 

Clark-CRF256X-Project-G-07-12-2016FMF Racing                                      www.fmfracing.com              310-631-4363

Powercore 4 muffler

Megabomb header

 

Millennium Tech                 www.mt-llc.com                                  920-893-5595

Cut stock seats (clean up)

 

CPR                                                                       cpracing2@yahoo.com                951-634-1527

Head Porting

 

Cycra Racing                                     www.cycraracing.com        740-929-0188

Pro Bend Hand Guards
Cycra Lite front fender

 

Tusk Off road                                   www.tuskoffroad.com                        800-336-5437

Front Steel braided brake line

Oversized 270mm front rotor

Rear Disc

Complete Wheel set  18” rear

Brake bolts kit

Sprocket Bolts kit

Dual Sport Kit with LED blinkers

Rear View Mirror right side inside down on the left to look under your arm

Lightweight Tusk Lithium battery

Tusk Hand Shields with integrated spot for blinkers

Rear Brake Pedal

Shifter

Clark-CRF256X-Project-F-07-12-2016

 

Rocky Mountain ATV/MC              www.rockymountainatvmc.com        800-336-5437

O-ring Chain from Primary Drive

 

Uni Filter                                           www.rockymountainatvmc.com        800-336-5437

Two-stage Air Filter

 

CV4                                                    www.cv4.net                           800-874-1223

Formed Silicone Coolant hoses

High pressure radiator cap

 

Renthal                                              www.renthal.com                   877-736-8425

Stock front 13T sprocket

Rear 49T sprocket Twin Ring

604 Fat Bars

Dual compound grips

Front & rear brak pads

Big bar mounts

 

Dunlop Tire                                       www.dunlopmotorcycle.com 800-845-8378

AT81front  90/90-21

AT81 rear   110/90-18

 

Moto Seat                                          www.motoseat.com               951-258-5229

Custom Cool seat cover

 

Clark-CRF256X-Project-H-07-12-2016

Works Connection                            www.worksconnection.com   800-895-8292

Front brake cap

Rear Brake cap

Rotating front brake mount

Hour Meter and Mount

Steering Stem Nut

Elite Clutch Perch

ARC front Brake lever

Motor Plugs

Rear master cylinder guard

Chain Blocks

 

DeCal Works                   www.decalmx.com   815-784-4000
Graphics kit

 

Hinson Clutch Components             www.hinsonracing.com          909-946-2942
Fibers, steels, springs and Outer Cover kit.

 

IMS                                        www.imsproducts.com           800-237-9906
Pro Series foot-pegs

 

Motion Pro                            www.motionpro.com   650-594-9600
Titan Throttle tube

 

San Diego Powder Coating                 www.sandiegopowdercoating.com   619-956-0987
Sandblasting, powder coat valve cover and left side cover

 

Clark-CRF256X-Project-I-07-12-2016

Acerbis                       www.acerbis.com                               800-659-1440
Rear Chain Guide
Skid Plate
Plastic kit for bike

 

ICW Radiators                                  www.icwradiators.com          919-796-8084
Radiator repair and strengthening

 

Trail Tech                  www.trailtech.net                               360-687-4530
High output X-2 Head light with upgraded stator and Reg/Rec

 

Pro Moto Billet                                 www.promotobillet.com      866-466-4762
Kick-It Stand

 

Race Tech                                 www.racetech.com            951-279-6655
Suspension rebuild and service

 

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