"This pulls like my factory bike. And the suspension is awesome."
-An impressed Ryan Huffman said after getting off his TBT Racing prepared KX 250.

4-Stroke: Head Porting, Valves, Cams, and more...

$375.00

TBT was one of the first companies to do engine work on four stroke motocross machines. With James Povolny Jr's results from 2002 we have never looked back.

We completely dis-assemble your head or complete engine, replace any worn or broken parts. Port and texture the intake tract for maximum throttle response and fuel atomization. Port and Polish the Exhaust to maximize exhaust flow.

Valve Seats are cut on a Sunnen air table with a fixed center, that is far superior to the Serdi used by other companies.

1 piece Ti valves, Performance Cams, Valve spring kits, and Ignitions are also available.

How about leaving Tim Ferry's Factory YZ426 behind by 4 bike lengths on the start? That's exactly what National #48 James Povolny has done at every outdoor national since getting his TBT Racing ported CR450 back on the track. (August 2002)

2-Stroke: Cylinder and Head Modification.

Using the latest in computerized port modeling software and a state of the art Dynojet 250 Dyno, TBT finds the hidden horsepower in your stock top end.

TBT technicians clean, de-bur, reshape and texture the transfer port for crisp throttle response. Then shape, smooth and polish the exhaust ports for the widest possible spread of power. Lastly, the head is precision machined to match the cylinder modifications.

$325 per cylinder

Factory Flat Top Engine

Want to run a factory-style motor without taking a shop vac to your savings account? The flat top engine modification is the closest thing you can get to a works engine the average guy can afford. It includes porting and head modifications, flat top piston and all gaskets and labor. It flat rips. (RM125, KX250, RM250, YZ125 Call for more info)

$575

The Factory Motor

If money is not an object, TBT can build you a "factory" motor. We have access to 90% of the exotic parts, pieces & coatings that you'll find in the factory team's motors. It's isn't cheap, but having your shoulders pulled from their sockets has never been so much fun.