For this build, we started with a fairly beat-up 2005 KTM 300 EXC. We wanted to see how close we could get it to a new KTM 300 (minus the electronic start of course). We came pretty close, and Dirt Bike Magazine liked it so much that it ended up on the cover of the magazine.

Taking Photos for Dirt Bike Magazine

We did a full frame-up restoration on this bike, going over every part and bolt. We took our time with other projects in between, and it took nearly three months to complete.

We rebuilt the engine and checked every pivot point on the bike. We put in a new drive, bled the brakes, freshened up the suspension, and touched everything else up to make sure it was in perfect condition.

The 300 EXC Being Rebuilt

One big complaint on 300s is the vibration you can feel, and that was reduced with Crank Works working their magic on the crankshaft. Crank Works actually does a bunch of complicated math to calculate out the best place to add and or take away material on the crank webs to make the bike vibrate less. Nearly all top factory teams run a balanced crankshaft for optimal performance and less vibration. The crankshaft is also balanced to work perfectly with the piston you are using.

One thing I have been impressed with on these older KTMs is their durability. In many cases, their parts don’t wear out as quickly as other bikes and still work well even after a lot of use. Many of the parts we replaced were switched out only because they just looked too beat up, like the plastic and pipe.

There are so many important parts of a build like this, but our key areas of focus were on the motor and suspension. You can have a great time on a bike that has these two areas in good shape. Many of the other parts we added to this build improved comfort, functionality, and (of course) looks.

The Finished Bike

After all of this work, we ended up with a bike that is close to as good as a new KTM that will last us another 10 years on the trail.

Products Used for this Build

 Hot Rod Complete Crankshaft Assembly Hot Rods Crankshaft Main Bearing and Seal Kit Vertex Piston Kit Standard
Hot Rods Complete Crankshaft Hot Rods Crankshaft Bearing and Seal Kit Vertex Piston Kit
V-Force 4 Reed Valve FMF Gold Series Pipe, “Gnarly Torque” FMF Turbine Core II Silencer
V-Force Reed Cage FMF Gnarly Pipe FMF Turbine Core 2 Silencer
Pivot Works Steering Stem Bearing Kit Pivot Works Shock Rebuild Kit Pivot Works Swing Arm Bearing Kit
Pivot Works Steering Stem Bearing Kit Pivot Works Shock Rebuild Kit Pivot Works Swing Arm Rebuild Kit
E Line Carbon Fiber Pipe Guard Cycra Radiator Shrouds Cycra CRM Ultra Pro Bend Racer Pack 1-1/8" Bars
E Line Carbon Pipe Guard Cycra Shrouds, Side Panels and Mud Flap Cycra Ultra Pro Bend Racer Pack
Uni Air Filter CV4 Radiator Hose Kit CV4 High Pressure Radiator Cap
Uni Two-Stage Air Filter CV4 Coolant Hoses CV4 High Pressure Radiator Cap
Renthal Twinring Rear Sprocket Renthal 1 1/8" Fat Bar Renthal Kevlar Grips – Half Waffle
Renthal Rear Twinring Sprocket Renthal Fatbar Renthal Kevlar Grips
Dunlop Geomax AT81 Tire Dunlop Geomax MX3S Tire Motoseat Ribbed Traction Seat Cover
Dunlop AT81 90/90×21 Dunlop MX3S 110/100×18 Motoseat Seat Cover
Works Connection Front Brake Reservoir Cap Works Connection Clutch Reservoir Cap Hinson Clutch Plate and Spring Kit
Works Connection Front Brake Cap Works Connection Clutch Reservoir Cap Hinson Fibers, Steels, Springs and Outer Cover
Tusk Oversized Floating Typhoon Brake Rotor Kit, Front Tusk Stainless Steel Typhoon Brake Rotor, Rear Tusk Impact Rim
Tusk Oversized Rotor Tusk Rear Disc Tusk Rim
Tusk Motorcycle Spoke Kit Tusk Brake Rotor Bolt Kit Tusk Folding Shift Lever
Tusk Spokes Tusk Brake Bolts Kit Tusk Shifter
Tusk Aluminum Brake Pedal TM Designworks Rear Chain Guide and Slider Kit Trail Tech X2 Dual Sport Headlight
Tusk Rear Brake Pedal TM Designworks Rear Chain Guide and Slider Trail Tech X2 Headlight
Trail Tech Kickstand Primary Drive 520 ORM O-Ring Chain Primary Drive Sprocket Bolt and Nut Kit
Trail Tech Kickstand Primary Drive O-Ring Chain Primary Drive Sprocket Bolts Kit
IMS Fuel Tank IMS Pro-Series Foot Pegs Klotz R-50 2-Stroke Oil
IMS Fuel Tank IMS Pro-Series Pegs Klotz R-50 2-Stroke Pre-Mix
Attack Graphics Custom Graphics OEM Parts, 54803094100
Attack Graphics Custom Graphic Set OEM KTM Frame Guards

Do you have an old, beaten bike that could be freshened up to look like new? What do you think about this KTM 300 EXC project bike? Let us know your thoughts in the comments!

The Original KTM 300 EXC Bike 2005 KTM 300 EXC Project Build
Before After

Technician Disclaimer

By Jay Clark