I measured my 83 midnight maxim 750 and it stands 31 in. from ground to top of seat
The seat height of a 1981 Yamaha Maxim 550 is 29.3 inches. That height not really adjustable, but frame modifications would probably lower it.
Under the seat
The seat height on a 2001 Yamaha yz80 33.6 in.
It is under the seat...inside the "air box"...
780mmm
Overall height=37.8" Seat Height=29.9"
Most Yamaha TTR125 bikes are an average 30.5 inches in seat height.
There is a motor in between your legs!
31.7 inches
39.1 i think
32.8 inches for a 2009 RI
20 - 21.5mm off the seat of the bowl gasket to the top of the float