Rebuild & Restore
Restore compression, correct wear and return the engine to dependable operating condition using properly selected replacement components.
Discuss your rebuild →Engine Service
Tokyomods Engine Program
Dirt Bike & ATV Engine Rebuilding
Stock-spec rebuilds. Performance engine packages. Full race-engine preparation. Tokyomods builds two-stroke and four-stroke engines around your motorcycle, riding application, performance goals and budget.
Founded 2005
Performance experience
Factory Racing
Proven background
2-Stroke + 4-Stroke
Complete engine service
Power + Reliability
Built as one system
We build results
Race experience working for you
Tokyomods was founded by former factory mechanic Ron Wood to bring factory-level racing and engine-preparation experience to motorcycle and ATV riders.
Ron's background includes Factory Honda, Kawasaki racing and TRD engine work. Today, that experience guides every Tokyomods engine program—from dependable stock rebuilds to complete motocross, supercross, desert, off-road, supermoto and ATV performance packages.
The goal is not to install the most expensive parts. It is to select, inspect and assemble the right combination for the engine, rider and intended use.
“We don't just build race bikes. We build engines that deliver the power, rideability and reliability the rider actually needs.”
Every engine is evaluated before work begins. After inspection, we provide a detailed estimate based on condition, required parts and performance goals.
Choose your build
One engine shop. Three clear goals.
A trail bike, weekend race bike and professional competition engine should not receive the same build. We develop the package around how the motorcycle will be used.
Build More Usable Power
Improve torque, throttle response and power delivery with components and machine work selected to operate together—not as unrelated modifications.
Plan your engine package →Race-Engine Preparation
Purpose-built engine packages for motocross, supercross, desert, off-road, supermoto and ATV competition, developed around the rider and race program.
Start a race build →Complete engine capabilities
Two-stroke and four-stroke services
From a top-end refresh to complete case splitting and rebuilding, Tokyomods can inspect and service the complete powerplant.
Four-Stroke Engines
Complete maintenance, rebuilding and performance preparation for modern high-output four-stroke motorcycle and ATV engines.
- Top-end rebuilding
- Complete engine rebuilding
- Case splitting and inspection
- Cylinder-head porting
- Cylinder-head rebuilding
- Valve and valve-train service
- Valve-guide installation
- Precision valve-seat cutting
- MoldStar 90 valve-seat installation
- Cylinder surfacing and honing
- Stock crankshaft rebuilding
- Race crankshaft rebuilding
- Transmission and clutch inspection
- Big-bore and stroker packages
- Throttle-body modification
- Injector and throttle-body cleaning
- REM isotropic superfinishing
Two-Stroke Engines
Precision two-stroke rebuilding and preparation focused on sealing, compression, crankshaft condition and clean, responsive power delivery.
- Top-end rebuilding
- Complete engine rebuilding
- Engine pressure testing
- Case splitting and cleaning
- Crankshaft inspection
- Crankshaft rebuilding
- Main bearings and seals
- Cylinder inspection and honing
- Transmission inspection
- Clutch inspection
- REM transmission finishing
- Carburetor rebuilding
- Application-specific carburetor tuning
Cylinder-head precision
The head controls the engine
A properly rebuilt engine depends on correct airflow, valve sealing and valve-train condition. Tokyomods provides complete cylinder-head rebuilding, porting and precision valve-seat service.
Cylinder heads are cleaned and inspected before the required machine work and components are determined. Valve options may include OEM, stainless-steel or titanium components depending on the model, application and build goals.
Serdi Valve Equipment
Precision valve-seat machining for correct sealing and geometry.
Head Porting
Airflow development matched to the engine and intended power delivery.
Valve-Train Service
Inspection and replacement of valves, springs, guides and related components.
Complete Head Packages
Stock rebuilds through complete competition cylinder-head assemblies.
What happens next
A clear engine-building process
We do not guess at the condition of an engine or quote unnecessary parts before inspection. The final scope is based on what the engine needs and what you want it to do.
Tell us about the bike
Provide the year, make, model, symptoms, riding application and build goals.
Send or deliver it
Contact us before shipping an engine, cylinder head or related components.
Inspection
We disassemble, clean and inspect the components required to define the job.
Detailed estimate
We review the required work, replacement parts, options and expected completion time.
Precision build
Approved machine work, component preparation and assembly are completed as one package.
Built around the application
Different disciplines demand different power
We match the engine package to the traction, rpm range, response and durability required for the motorcycle and riding environment.
Engine-service FAQ
Before you send your engine
How do I start an engine rebuild with Tokyomods?
Contact Tokyomods with the motorcycle or ATV year, make and model, the reason for service, known engine history, current symptoms, riding application and performance goals. We will explain what to send and the next step for your specific project.
Can you quote the complete rebuild before inspecting the engine?
A useful final estimate requires inspection. Internal wear, damaged components and required machine work cannot always be confirmed from the outside. Once the engine or cylinder head is received and evaluated, we will provide a detailed estimate before proceeding with additional work.
Do you build stock engines as well as race engines?
Yes. Tokyomods provides stock-spec rebuilding, reliability-focused refreshes, performance engine packages and complete competition builds. The right package depends on the motorcycle, rider, intended use and budget.
What is included in a complete engine rebuild?
The exact scope depends on engine condition. A complete rebuild may include disassembly, cleaning, inspection, crankshaft service, bearings, seals, gaskets, piston and cylinder work, cylinder-head and valve-train service, transmission and clutch inspection, required machine work and reassembly. Your estimate will identify the work and components for your engine.
Can you build an engine for a specific type of riding?
Yes. A motocross engine, desert engine, technical off-road engine, supermoto engine and sport ATV engine require different power characteristics. We use your riding application and goals to help determine the compression, airflow, valve-train, crankshaft and supporting component strategy.
How long will my engine rebuild take?
Completion time varies with engine condition, machine work, parts availability and the complexity of the package. Tokyomods will provide an expected completion time after inspection and preparation of the detailed estimate.
How should I prepare an engine for shipping?
Contact Tokyomods before shipping. Drain all fluids, protect exposed openings, package the engine securely and include your complete contact, motorcycle and service information. We will confirm what components should be included for your particular job.
Ready to build it right?
Tell us what you ride, what the engine is doing and what you want from the finished build. Tokyomods will help develop the right path forward.