Checking The Valve Seats; Valve Guide - Ducati SCRAMBLER 800 Workshop Manual

Checking the valve seats

Visually check the seats: they do not have to be excessively recessed or feature pitting or cracks.
In case the seat is slightly damaged, grind it using suitable 45° grinders and then lap the valves and check
for any leakage. If the valve seats are excessively damaged, fit oversize seats. Spare seats are available
with 0.03 and 0.06 mm oversized outside diameters.

Valve guide

Check the internal surface of the valve guides: there should be no signs of deformation or cracking.
Thoroughly check the dimensions of the valve guide.
Measure the inside diameter with a suitable gauge.
Measure the diameter at different positions of the valve guide.
Check the diameter of head housings and choose the oversized valve seat that will give an interference fit
of 0.11÷0.16 mm.
The valve seats are available as spare parts with outer diameter oversized by 0.03 and 0.06 mm.