Every 16,000 miles or 2 years
Service Interval
2–4 hours
Estimated Time
$33
DIY Cost
$428
Shop Cost
Difficulty:
Hard
Overview
The 2021 KTM 390 Duke requires valve clearance check every 16,000 miles or 2 years. Regular valve clearance maintenance extends engine life and maintains peak performance. This guide covers the complete procedure for both DIY mechanics and those seeking shop estimates.
⚠️ Important: Valve clearance must be checked on a cold engine. Incorrect valve clearance can cause engine damage or reduced performance.
Tools Needed
🔧 Feeler gauges
🔧 Cam cover gasket set
🔧 Torque wrench
🔧 Shims (various sizes)
🔧 Socket set
🔧 Valve adjustment tool
Supplies Needed
📦 Cam cover gasket
📦 Valve shims (if adjustment needed)
📦 Engine oil
📦 Thread locker
Step-by-Step Procedure
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1Ensure the engine is completely cold (at least 3 hours after last run).
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2Remove the fuel tank, side panels, and any obstructions to access the cam cover.
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3Remove the cam cover carefully and set aside the gasket.
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4Rotate the engine to Top Dead Center (TDC) on the compression stroke using the crankshaft bolt.
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5Use feeler gauges to measure clearance between cam lobe and valve follower for all valves.
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6Compare measured clearances to manufacturer spec (typically 0.08–0.18mm intake, 0.15–0.25mm exhaust).
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7If clearance is out of spec, remove camshaft(s) and replace shims to achieve correct clearance.
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8Reinstall camshaft(s) ensuring correct timing alignment.
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9Install new cam cover gasket and torque cover bolts to spec.
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10Reinstall fuel tank and panels. Start engine and listen for any ticking or unusual noise.
💰 Cost Breakdown
Shims (if needed)
$5–40
Cam cover gasket
$15–35
DIY Total
$20–75
Shop labor (3 hr)
$150–300
Shop Total
$180–380