Racer X Films: CRF250R Off Road

January 20, 2015 11:30am | by:

Video: Simon Cudby
Text: David Pingree

Old motocross bikes out of the current model years that were once raced hard can end up in a heap of parts never to be raced again. Well, Jay Clark found just such a beat bike and went to work to make a off-road machine.

This bike was purchased as a full basket case from an ex-racer for under $1,000. (Summer time in California is the best time for good deals on bikes as it is too hot for most shoppers.) We feel we could have gotten this bike in great working order for under $2,000. With our initial investment we would have been under $3,000 for a great running fuel-injected trail bike.

I have always liked the Honda 250X for off-road and trail use, with the starting button being my favorite feature and the carburetor being my least favorite. So, the goal here is to make a full Trail/Off-Road fuel injected CRF270R/X. The main downside being of course that we wouldn’t have electric start. However, we were hopeful the larger motor, fuel injection, updated chassis, and suspension would have a good ultimate “budget” trail machine.  

A cylinder Works 3.2mm over big bore kit drops right in. A stage one cam gives us plenty of grunt with not much loss of top-end power.  

An FMF pipe with their most quiet spark arrestor insert kept us legal and happy to the ears. A Vortex ECU was able to be adjusted with just a few clickers. The throttle body was fully cleaned and modified by Wade at Injectioneering. He also softens up the throttle spring to allow for quicker action. 

For the motor we had CrankWorks “heavy-up" the crank before the rebuild and balance to the piston. This cuts down on vibration and helps with a bit more trail tractability power.  

For off-road and trail use the stock R tank would not get us too far so we used a much larger 2.9 gallon IMS tank that will now be able to go the distance. A Cycra full-coverage skid plate and hand shields were added to make sure we were ready for the trails.

Race Tech set up the suspension for slow trail use in very tight conditions.   

For tires, we used Dunlop’s new AT81 tires front and rear for most use. However, we wanted to try a Dunlop D803 Trials tire for our dry, rocky SoCal conditions. 

We also added a Pro Moto Billett Kickstand for ease on the trails. 

Bike runs great on 91 octane pump fuel.

Not every modification is necessary for a good trail bike, but sometimes it's fun to play a bit, so Jay went all-out to make an ultimate trail bike.

Nearly every major product for this project can be obtained directly from Rocky Mountain ATV/MC | www.rockymountainatvmc.com | 800-336-5437

Cylinder Works: 3mm Big bore Cylinder Kit 269cc. Includes Forged Vertex Piston and Cometic Top-End gasket kit. | www.cylinder-works.com515-251-4070

Hot Cams: Stage-One Cam Shaft | www.hotcamsinc.com | 515-402-8200                                                 

FMF Racing:  | www.fmfracing.com | 310-631-4363                        

Q4 Muffler                          

Megabomb Header                   

Injectioneering | www.injectioneering.com | 310-953-2915

Throttle Body Modifications                           

Cometic | www.cometic.com | 800-752-9850         

Complete Gasket Kit                                             

IMS | www.imsproducts.com | 800-237-9906                        

Oversized Fuel Tank

MotoTassinari | www.mototassinari.com | 603-298-6646                              

Air4orce Air Boot                                     

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

Full Coverage Skid Plate  

Full Plastic Kit 

Pro-Ben Full Wrap Around Hand Guards

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

Two-stage Air Filter                                               

CV4 | www.cv4.net | 800-874-1223                        

Formed Silicone Coolant Hoses in Yellow

High Pressure Radiator Cap

Renthal | www.renthal.com | 877-736-8425

Stock Front Sprocket

Rear 48T Sprocket                  

997 Twin Walls                                       

Dual Compound Grips             

Brake Pads Front and Rear

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

AT81 Front 90/90-21 Trials Tire

AT81 Rear 110/90-18 and D803 Trials Tire   

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

Custom Cool Seat Cover with Slightly Lowered Foam  

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

Elite Perch              

Front Brake Cap  

Rear Brake Cap 

Chain Blocks  

Engine Plugs 

Oil filler Plugs

Hour Meter  


Ti Foot Peg Set

Hinson Clutch Components | www.hinsonracing.com | 909-946-2942

Fibers, Steels, Springs and Outer Cover Kit. 

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

270mm Oversized Rotor/Adaptor Bracket 270mm   

Rear Disc                               

Complete Wheel Set   

Front Steel Braided Brake Line  

Rear Brake Pedal  

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

All OEM parts Clutch cable, Rad Louvers and miscellaneous hardware.    

O-ring Chain | Primary Drive   

Race Tech | www. racetech.com | 951 279 6655 

Freshen up the suspension with new fluids and seals 

Pro Moto Billet | www.promotobillet.com | 866-466-4762

Kick-It Stand  

Rocket Performance | www.rocketexhaust.com | 951-471-3500                     

Vortex X-10 ECU and Mapping  

Pivot Works | www.pivotworks.com | 515-402-8000

Linkage Kit

Steering Stem Kit 

Fork and Shock Rebuild Kits

ICW Radiators | www.icwradiators.com | 919-796-8084 

Radiator modification welding, bracing seam welding and additional tank  $250

Crank Works | www.crankworks.com | 480-897-1746 

Balance the Crankshaft

Attack Graphics | www.attackgraphics.com | 801-465-4382         

Custom Graphic set