The 140FZ doesn't have the mounting lug on the rear of the carb to use this mount. The 140 Sport does...but the 140FZ pre-dates the mount. If you engine has the big nobby lug on the rear of the carb like the photo below then its a 140L. The L stands for 140FZ-L which is a limited edition motor. This motor was sold for about 3-4 years and it was a limited edition as it was designed with this motor mount as a system. In the USA the engines were sold seperately from the mounts as guys in the USA use the Hyde mounts. But the Limited shakes a bit more than the 140FZ as it has the crankshaft ring on it. The super charger is a bit stronger and the 140L makes a couple 200-300 more rpm than the original 140FZ

This is a photo of the rear of the carb and how it mounts. It doesn't even touch the mounting lugs on the side of the engine. It attaches to this nub and then the nose ring sits around the front bearing housing and the engine rotates about 5-10deg back and forth around the prop shaft.

This picture is a DZ engine but the mounting LUG on the rear of the carb has 3 bolt holes then there is a spot up higher near the air intake of the carb that attaches the little shock absorber.

For vibration it makes ahuge difference if the prop is well balanced. Next is the high the top end rpm like up around 8800 or so the lighter the load on the engine and the better vibration levels will be. If you load the engine down to 8000rpm it can shake like a mother. But turn it at 8800 and it is quite a bit smoother running.
Especially the 140FZ its a pretty smooth motor compared to the other 140's


There may be other options for you. The Dave brown Vibradamp mount can help and would work easily on your model.

Vibra-Damp Sport Rail Mount....photo below as well