Dedicated Subsystem WorkbenchPlatform Gen: 2005–2025

2025 Yamaha YZ125 Valve Clearance Specs & Shim Calculator

Cold valve clearance specs for 2025 Yamaha YZ125: intake mm, exhaust mm, inspection intervals and replacement shim calculator.

Technical PassportOEM VERIFIED

Engine

125cc

Cooling

Not Available

Final Drive

520 Chain

Engine Oil

0.66 L (0.70 US qt) Periodic Gearbox Oil Change (0.70 L Total Overhaul)

Spark Plug

NGK BR9EVX / BR9EG

Front Tire

80/100-21 51M

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Gen 2005–2025

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2005 through 2025.

SPECS-TO-CART BUNDLESFactory Direct-Fit Maintenance Bundles Available

1-Click verified Motul engine oil service kits, race filters, spark plugs, and brake fluid pre-measured for this 2025 Yamaha YZ125.

Configure Service Bundles→

Select Model Year:(Active: 2025)
21 Production Years (2005–2025)

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

Suggested Items4 Verified Workshop Consumables Available for this Job

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Factory Valve Clearance & Shim Calculator

OEM Workshop Tolerances

Cylinder head valve lash specifications, timing TDC mark alignments, and interactive replacement shim calculation engine.

Adjustment Mechanism: Not Applicable (2-Stroke Reed & YPVS Exhaust Valve)

Active Valve Range (INTAKE)

0.00 - 0.20 mm VForce4R Carbon Reed Petal Tip Lift Limit

0.000 - 0.008 in Reed Petal Tip Lift Limit

Nominal Mid-Spec Target

0.15 mm

Ideal cold lash assembly setting

Shim Diameter / Tappet

Not Applicable (2-Stroke Reed & YPVS Exhaust Valve)

Bucket-and-shim interface

Measurement Condition

Cold Engine (≤ 35°C / 95°F)

TDC compression stroke only

Interactive Shim Sizing Calculation Engine: New Shim = Current Shim + (Measured Clearance - Target Clearance)

1. Feeler Gauge Measured Clearance (mm)

Factory intake tolerance: 0.00 - 0.20 mm VForce4R Carbon Reed Petal Tip Lift Limit

2. Currently Installed Shim (mm)

Measured with micrometer or read laser-etched face

TDC Crankshaft Timing Index

YPVS Power Valve Governor pushrod aligned; clean carbon from exhaust slide valves every 10–15 hours

Feeler Gauge Technique

Measure Piston-to-Cylinder Clearance (0.040–0.045 mm) and Ring End Gap (0.35–0.50 mm) inside 54.00 mm cylinder bore

Official NHTSA Safety Recalls & Technical Bulletins

0 Open Campaigns (Clean)

U.S. Department of Transportation compliance database (Title 49 U.S.C. Chapter 301).

Verify VIN on NHTSA.gov

No Active Federal Safety Recalls Reported

The U.S. DOT National Highway Traffic Safety Administration (NHTSA) records zero open safety recall campaigns for the 2025 Yamaha YZ125 platform. Always check your individual 17-digit VIN at an authorized dealership or via NHTSA.gov for individual recall completions.