Racer X Films: CRF250R Off Road

January 20, 2015, 4:30pm

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.com | 515-251-4070

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