Desmo shims for the Parallel twin

Many riders with the desmo head on their PT have come across the need for thicker closing shims. With my 500 head without shims I needed to start from scratch. Having some shims left over from belt drive desmo heads, the valves only needed to have a new groove in the stems roughly 4~5 mm lower than the original to have them instead.
As the 500 head needed new valve seats, larger 600SS/Monster valves were taken and those modified with new grooves, and now desmo adjustment can be done with standard available shims from your local Ducati dealer. Problem solved!

2014-01-25 18.25.57

1 thought on “Desmo shims for the Parallel twin

  1. hello arthur. I always keep reading your articles on parallel twins, very interesting. I wanted to ask you for information about the rockers of the gtl no desmo. When overhauling the cylinder head of a 1976 GTL 500, I saw that the rocker arms have a spring and shim washers. Some have greater axial play and some have less. I looked at the manual but it only talks about the radial play of the rocker arms, and that is good. Are there any parameters? The axial play must be adjusted with the shim washers, but are there any tolerances? Thanks

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