Dedicated Subsystem WorkbenchPlatform Gen: 2014–2026

2016 Honda Grom (MSX125) Cylinder Compression & Leakdown Diagnostic Engine

Factory compression specs for 2016 Honda Grom (MSX125): standard pressure 145 - 185 PSI (1000 - 1276 kPa), service limit 120 PSI, dry vs wet test diagnostics and acoustic leak stethoscope.

Technical PassportOEM VERIFIED

Engine

124cc

Cooling

Air-Cooled

Final Drive

420 Chain

Engine Oil

0.90 L (0.95 US qt)

Spark Plug

NGK CPR6EA-9

Front Tire

120/70-12

Gen 2014–2026

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2014 through 2026.

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 2016 Honda Grom (MSX125).

Configure Service Bundles→

Select Model Year:(Active: 2016)
13 Production Years (2014–2026)

2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

Suggested Items4 Verified Workshop Consumables Available for this Job

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Cylinder Compression & Leakdown Diagnostic Engine

Multi-Cylinder Dry vs. Wet Test Bench, Differential Pressure Regulator & Acoustic Stethoscope Locator

Ratio: 10.0:1Std: 145-185 PSILimit: 120 PSIWhip Adapter: M10 x 1.0

Centrifugal Decompression Cam Weight

CRITICAL THUMPER NOTE: Engine features Centrifugal Decompression Cam Weight. At cranking speed (< 400 RPM), the decompressor holds an exhaust valve slightly cracked open. Normal cranking reading with active decompressor is 80 - 95 PSI. To verify true full cylinder compression (145-185 PSI), either temporarily deactivate the decompressor pin or verify via 100 PSI leakdown testing at TDC.

Diagnostic Presets:

Cylinder #1 (Single)IN-SPEC

171PSI(1179 kPa)

Single Cylinder Pressure: 171 PSI (Service Limit: ≥ 120 PSI)

All cylinders demonstrate strong, balanced mechanical sealing. Piston ring packs, cylinder cross-hatch, and valve seats are within factory specification.

Official Workshop Manual Compression Test Protocol

Step 0 of 5 Completed

Step 1: Engine Operating Temperature

Run engine until coolant reaches 60°C - 80°C (140°F - 176°F). Cylinder expansion brings rings and pistons to true operating clearances.

Step 2: Spark Plug Removal & Port Clean

Blow compressed air around spark plug wells to eject grit, then remove all spark plugs. Thread in M10 x 1.0 whip adapter hand-tight with fresh O-ring.

Step 3: Wide-Open Throttle (WOT) Lock

Hold throttle grip fully wide open (or lock throttle bodies open) to eliminate intake butterfly vacuum restriction and ensure 100% volumetric cylinder filling.

Step 4: Battery Tender Voltage Stabilization

Connect a 12V shop battery tender or booster. Starter must sustain uninterrupted cranking speed (350 RPM) to build maximum dynamic stroke pressure.

Step 5: Crank 4-6 Compression Strokes

Engage starter until gauge needle ceases rising (typically 4 to 6 strokes). Record maximum peak pressure and compare against the OEM limits above.

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 2016 Honda Grom (MSX125) platform. Always check your individual 17-digit VIN at an authorized dealership or via NHTSA.gov for individual recall completions.

OEM Workshop Archives

Official Factory Service Bulletins & Field Updates

1 Documented Bulletin

Bulletin #HON-16V661Safety Recall KC4 (MTB 15216): Grom (MSX125) Fuel Pump Replacement & ECM Initialization

Source: Honda_Grom_Recall16V661_8528.pdf

Mandated Torques:Torque: 12 N·m (1.2 kg-m, 9 lbf·ft) (Fuel Pump Base Flange Nuts - Crisscross 2-3 Stages)Torque: 10 N·m (7 lbf·ft) (Fuel Tank Shroud Screws)

Consumable Specs:Genuine Fuel Pump Gasket 17572-GGL-J00Genuine Dust Seal 17518-GGL-J00SCS Short Connector 070PZ-ZY30100 for ECM Reset

Genuine Part Numbers:06160-K26-31617572-GGL-J0017518-GGL-J00

HONDA GROM 125 FUEL SYSTEMExploded View: In-Tank Fuel Pump & ECM Calibration (Safety Recall 16V-661 / KC4)

KIT # 06160-K26-316NHTSA 16V-661

Remedy Fuel Pump Assembly (Green Paint Mark)

Genuine Kit # 06160-K26-316 (Supersedes 06160-K26-306)

Base Nuts: 12 N·m (1.2 kg-m, 9 lbf·ft) Crisscross

CRITICAL SAFETY & EMISSIONS RECALL (Recall 16V-661 / Service Bulletin Grom125 #1 / KC4). Replaces defective fuel pump prone to resin impeller swelling and pump seizure. COUNTERMEASURE IDENTIFICATION: Verified by a green paint mark on the top of the pump housing and a black cap cover. DO NOT USE old recall kit 06160-K26-306.