top of page
IMG_9719.jpeg

Valve Train Service

Our Valve Train Service is a comprehensive inspection, correction, and performance optimization procedure for high-performance and street motorcycles. This service ensures correct valve timing events, optimal sealing, mechanical reliability, and, when requested, measurable power gains through precision cylinder head modification.

​

This service is suitable for sportbikes, race bikes, and performance builds, particularly high-revving inline-4 and twin-cylinder engines where valve train accuracy directly impacts reliability and output.

1. Valve Clearance Inspection (Valve Lash Check)

​

Objective

Verify that valve-to-cam clearance (lash) is within manufacturer specifications under cold-engine conditions.

​

Procedure

  • Remove bodywork, fuel tank, airbox, and ignition components as required

  • Remove valve cover and inspect cam lobes, journals, and buckets

  • Rotate engine to Top Dead Center (TDC) per cylinder

  • Measure intake and exhaust clearances using precision feeler gauges

  • Record all values and compare to OEM specifications

​

Technical Importance

  • Tight valves → loss of compression, hard hot starts, burnt valves

  • Excessive clearance → valve train noise, accelerated wear

  • Critical on high-RPM engines (e.g., track or race applications)

 

Deliverable: Full clearance measurement chart for customer documentation.

.

2. Valve Adjustment (Shim / Screw-Type Correction)

 

Objective

Restore all intake and exhaust valve clearances to ideal specification or performance target range.

​

Shim-Under-Bucket Systems (common on sportbikes)

  • Remove camshafts following proper timing procedures

  • Measure and calculate required shim thickness

  • Install new precision shims

  • Reinstall cams and verify cam timing alignment

  • Torque cam caps to manufacturer specifications

  • Re-measure all clearances after reassembly

​

Screw-and-Locknut Systems (common on air-cooled / older bikes)

  • Adjust clearance via tappet screw

  • Lock and verify clearance

  • Confirm uniformity across cylinders

​

Optional Performance Adjustment

For race applications, clearances may be set strategically within tolerance range to optimize:

  • Valve stability at high RPM

  • Thermal expansion margin

  • Aggressive cam profile compatibility

3. Cylinder Head Performance Modifications

​

This portion applies to customers requesting increased horsepower and improved volumetric efficiency.

​

A. Porting & Polishing

  • CNC or hand port reshaping for improved airflow velocity

  • Intake port smoothing (maintaining proper surface texture for fuel atomization)

  • Exhaust port polishing for reduced flow restriction

  • Bowl blending under valve seats

  • ​

Goal: Increase airflow CFM while preserving port velocity and throttle response.

 

B. Multi-Angle Valve Job

  • 3-angle or 5-angle valve seat cutting

  • Precision concentricity verification

  • Improved valve sealing and flow transition

​

Benefits:

  • Increased airflow at low and mid valve lift

  • Better combustion efficiency

​

C. Valve Upgrades (Optional)

  • Titanium intake valves

  • Stainless steel exhaust valves

  • High-performance valve springs

  • Retainer upgrades (titanium options)

​

Used for:

  • High-lift camshafts

  • Increased RPM limits

  • Forced induction builds

 

D. Camshaft Installation & Degreeing (Optional)

  • Install performance camshafts

  • Degree cam timing using degree wheel and dial indicator

  • Adjust cam timing for optimal intake centerline and exhaust lobe separation

​

Critical for:

  • Maximizing dyno-verified gains

  • Matching cam timing to compression ratio and exhaust system

 

Expected Benefits

​

Reliability Service Only:

  • Smooth idle

  • Stable hot starts

  • Improved compression

  • Extended valve life

Performance Package:

  • Increased horsepower and torque

  • Stronger midrange

  • Higher RPM stability

  • Improved throttle response

  • Dyno-tuning ready configuration

​

Recommended Service Intervals

  • Street motorcycles: Every 12,000–16,000 miles (check manufacturer spec)

  • Track/race bikes: Every 1–2 race weekends or 1,000–1,500 miles

  • High-compression or modified engines: More frequent inspection required

​

Why This Service Matters

Improper valve clearance is one of the most common causes of:

  • Burnt exhaust valves

  • Compression loss

  • Hard hot starts

  • Idle instability

  • Premature camshaft wear

 

For performance engines (especially high-revving platforms like inline-4 supersports), precise valve train setup is not optional — it is foundational.

bottom of page