928 questions
 

First, the upper idler pulley for the timing belt, it does not seem to contact the belt? Is this just for slop at high rpm?

Second, the plastic cover over the wiper motor, under the hood, it goes across from one side to another, where would I find a new one? other than a dealer.

Correct the small pulley over the tensioner pulley is just for belt slack.

vendors for the rear wiper cowel cover are:
..here on pelican !! site sponsor

928specialist.com..spe3ak with jeannie or JR
************. speak with rodger

the top roller is to control belt flutter as the engine expands from cold to running temperature.
If you do a bit of searching 928International is having its yearly half price sale in December all used parts are half price good luck

Cowl panel cover is so flimsy a new one is the only way to go. If yours is missing be sure to get all the leaves and junk out of the cowl area.

Yes, there are plenty of leaves and junk.
So a dealer is my only option I guess.

Fred see post #3
Usually 928Intl has good used parts its worth a check