The Yamaha TZ700/750, the"beast" originally has a 64 x 54 bore stroke (694,5 ccm) but already later in 1973 this was changed into 66,4 x 54 mm (747,6 ccm).

The first 700 ccm machines were claimed to have 80 PS at 10.500 rpm, the 750 ccm version (TZ750A) had already 100 ps at 10.500 rpm. carburetors were Mikuni VM34SC's.

Yamaha TZ700 1973 YMENV Workshop

Here you can see that the engine was a "double-up" Yamaha TZ350, primary transmission went by a "middle gear" that also drove the waterpump.

Yamaha TZ700 engine layout

The "full" 1974 TZ750A in all its glory. Soon thereafter the exhaustpipes were "braided" upwards, so it is easy to distinguish the early from the later TZ750's.

Yamaha TZ750 1974

Here first 2 pictures of the 1977 TZ750D machine. On the large photo you can see a lot of details.

Yamaha TZ750 1977

Yamaha TZ750 1977