Fostex model 80 left tape counter sensor 8251160 000 This is the cap that's

This is  the cap that's used on the Tascam tension arms

they often keep their top level PCB numbers the same in each unit so you need to check if you have the same 5xxxxxxxx number to be sure

Fostex R8 connector board 8251840-101 very clean and tidy with clean pins from a low mileage machine from a smoke

Standard 80mm heavy balanced flywheel used in all of the later Teac and Tascam models

Fostex model 80 left tape counter sensor 8251160 000 This is the cap that'sThis is the actual sensor that sits in the housing of the right hand side. You have to remove the molex plug to get it through looking from the back of the plug lugs up its red white 1 white 2 blue 3 yellow 4 with one starting on the left