Ducati running rough or hard to start: desmo valve clearance
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Applies to: Ducati Multistrada, DesertX and other desmodromic Ducatis
Symptoms
- Harder starting, rough idle
- Ticking from the heads
- Overdue for the valve service interval
Why it happens
Desmo valves are opened and closed by rockers with shims. Opening and closing clearances drift with wear and need checking at the service interval.
How to fix it
- Check the service interval for your model in the manual.
- With the engine cold, remove the valve covers and set each cylinder per the manual.
- Measure opening and closing clearances.
- Replace shims to bring clearances into spec, and check cam belt timing on belt engines.
Tools and parts
- Feeler gauges
- Valve shims
- Valve cover gaskets
What the factory service manual covers
Engine: desmo clearance specs, shim procedure, timing. The full procedure, specs and wiring diagrams are in the factory service manual for your machine.