Dedicated Subsystem WorkbenchPlatform Gen: 2017–2024

2018 KTM 390 Duke Valve Clearance Specs & Shim Calculator

Cold valve clearance specs for 2018 KTM 390 Duke: intake mm, exhaust mm, inspection intervals and replacement shim calculator.

Gen 2017–2024

Factory Platform Compatibility: All workshop fluid capacities, maintenance milestones, torque specifications, and consumables on this specification sheet are factory-identical across model years 2017 through 2024.

Select Model Year:(Active: 2018)

2017 2018 2019 2020 2021 2022 2023 2024

Engine

373cc

Drive

520

Cooling

Liquid-Cooled

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: 7.48 mm

Active Valve Range (INTAKE)

0.10 - 0.20 mm

0.004 - 0.008 in

Nominal Mid-Spec Target

0.15 mm

Ideal cold lash assembly setting

Shim Diameter / Tappet

7.48 mm

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: 0.10 - 0.20 mm

2. Currently Installed Shim (mm)

Measured with micrometer or read laser-etched face

TDC Crankshaft Timing Index

Align crankshaft TDC mark with engine timing index pointer

Feeler Gauge Technique

Angled stainless steel feeler gauge (cold engine ≤ 35°C / 95°F)

Official NHTSA Safety Recalls & Technical Bulletins

2 Active Campaigns

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

Verify VIN on NHTSA.gov

The U.S. National Highway Traffic Safety Administration reports 2 safety recall campaigns associated with this platform. Independent repair shops and riders should confirm that authorized dealership warranty remedies have been applied.

NHTSA #25V740000FUEL SYSTEM, GASOLINE:STORAGE:TANK ASSEMBLY:FILLER PIPE AND CAP

Received: 30/10/2025▼

Defect Description

KTM North America, Inc. is recalling certain 2024 390 Duke, 250 Duke, 990 Duke, Husqvarna Vitpilen 401, and Husqvarna Svartpilen 401 motorcycles. The seal on the fuel filler cap may develop cracks and leak fuel.

Safety Hazard / Consequence

A fuel leak increases the risk of fire or injury.

Factory Remedy & Repair Action

Dealers will inspect and replace the fuel cap gasket, free of charge. Owner notification letters were mailed December 15, 2025. Owners may contact KTM customer service at 1-888-985-6090. Vehicle Identification Numbers (VINs) involved in this recall will become searchable on NHTSA.gov March 31, 2026.

NHTSA #25V825000ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE

Received: 01/12/2025▼