Professional Motorcycle & ATV Engine Assembly
Professional motorcycle and ATV engine assembly requires far more than installing new parts. Proper engine building demands accurate measurements, correct component clearances, careful inspection, precision machining when necessary, and strict attention to cleanliness and assembly procedures.
Ken OConnor Racing provides professional two-stroke and four-stroke engine assembly services for motorcycles, dirt bikes and ATVs. With over 40 years of engine-building and machining experience, we specialize in single-cylinder engines for recreational riding, restoration, racing and high-performance applications.
Unlike shops that simply install replacement parts, we have the equipment and experience to inspect, measure, machine and assemble critical engine components in-house. Every engine is assembled with an emphasis on proper fitment, mechanical reliability and long-term performance.
Customers throughout the United States can ship their engines to Ken OConnor Racing for professional engine assembly and rebuilding services.
Engine Assembly
MOTORCYCLE & ATV ENGINE ASSEMBLY SERVICES – TWO-STROKE AND FOUR-STROKE
Modern motorcycle and ATV engines require specialized tools, precision measuring equipment, service information, and proper assembly procedures. Attempting an engine build without the correct equipment can result in damaged components, improper clearances, premature wear, or complete engine failure.
Our engine assembly process may include:
- Inspection and measurement of engine components
- Cleaning and preparation of parts
- Crankshaft and transmission installation
- Bearing, seal, gasket, and locking-tab installation
- Correct crankcase assembly procedures
- Cylinder and piston installation
- Cylinder head and valvetrain assembly
- Fastener tightening to proper torque specifications
- Verification of engine operation and critical clearances
- Two-stroke engine leak-down testing when applicable
WHY PRECISION MACHINING MATTERS DURING ENGINE ASSEMBLY
A successful motorcycle or ATV engine rebuild depends on more than installing new bearings, seals, gaskets and pistons. Every component must work together within the correct mechanical tolerances. Even new replacement parts should be inspected and measured before installation.
Crankshaft Inspection and Alignment
Crankshaft runout, connecting rod condition and bearing fits are critical to engine reliability. A crankshaft that is improperly aligned can contribute to excessive vibration, premature bearing wear and engine damage. When necessary, Ken OConnor Racing can perform professional crankshaft rebuilding and truing in-house.
Cylinder and Piston Fitment
Proper piston-to-cylinder wall clearance is essential for reliable operation. Cylinders are inspected for wear, taper and out-of-round conditions. When required, precision cylinder boring and honing are performed to establish the correct piston clearance and surface finish.
Cylinder Head and Engine Component Inspection
Cylinder heads, sealing surfaces, threads and other critical components are inspected for damage and dimensional accuracy. Required machining and repairs can be completed before final assembly, helping prevent problems that might otherwise be discovered after the engine is assembled.
Final Assembly and Verification
During assembly, critical clearances, component alignment and fastener torque are checked according to the engine’s requirements. Two-stroke engines are pressure and vacuum leak-down tested when applicable to help identify air leaks before the engine is returned to the customer.
Having machining and assembly services available in the same shop allows Ken OConnor Racing to maintain consistent quality throughout the rebuilding process.
Experienced Motorcycle and ATV Engine Builder
Ken OConnor Racing has been building race-proven engines for more than 40 years. Our in-house machining experience allows us to identify problems that may be overlooked during a basic parts replacement or engine assembly.
We work with motorcycle and ATV engines used for recreation, restoration, racing, and high-performance applications. Every engine is assembled using professional equipment and proven procedures—because an engine is no place to cut corners.
Customers can ship engines and components to Ken OConnor Racing for professional assembly. Visit our shipping page for packing instructions, or contact us before sending your engine
pricing
| Engine Assembly | |
| Single Cylinder Two Stroke | $750-$800 |
| Single Cylinder Four Stroke | $850 – $925 |
Final pricing depends on the engine model, condition, parts supplied, and work required. Contact Ken OConnor Racing before shipping your engine to confirm availability, pricing, and required components.
We ship and receive worldwide daily.