The return caps (along with the rocker-arm adjuster) are the effective clearance "shims" between the camshaft activating the close & open rocker arms that allows the precise opening and closing of the valves with minimal backlash and unpleasant tappet noise.
These usually require replacing with next size or two up; a feeler gauge is essential to check the clearances and size required.
More sizes below:
Add as many items as you wish to the same shopping cart, new gaskets and seals for example, and still only pay the same single fixed price shipping cost.
This component may have other applications within the Ducati model range, so please make sure you order the correct part number/s for your application.
Pro-workshop gasket sealant, 08C70K0234M - complete the job to professional standards.