Well you could have knocked me down with a feather
Went for a ride today on the Shadow and going very gingerly around bends, taking it easy in the greasy conditions. I got home and gave it a wash to get rid of the mud which sprays all over the headstock and radiator etc. I decided to check the tyre pressures.
20 psi in the rear (Manual says should be 33) and 25 in the front (manual says 33, manufacturers writing on tyre says 42!)
so put 35 in rear and 36 in front. Will ride tomorrow to see how things have improved..
There's a lot to be said for weekly checks

Now I know I have slow punctures.