You can see that the thrust bearing is positioned closer to the right-side clutch (the forward clutch IIRC, but Gadge will sort me out if necessary). For this to happen in the rest position of the pedal seems to suggest that the clutch spring for the forward clutch may have broken, preventing pressure from being applied to the forward clutch. The spring for the reverse clutch would still be functioning if that is correct.
If I am right you are going to have to remove the clutch shaft, complete with clutches, and dismantle it on the bench. You will immediately see whether there is a broken or missing component on one side of the thrust bearing. There are several threads available here at Outdoorking that will explain in detail how to do this job. However before we get too attached to this diagnosis, let's see what Gadge says - he has plentiful experience servicing these machines professionally.
