As per my observation deficiencies found in my current Bikes are as below,
Honda CD70 1996
Very poor milage at fullthrotle drive i.e. 32~35 Kmpl.
SUZUKI GSX 750 1984
Difficult to drive in slow traffic during extreme hot weather as the bike is totaly air cooled & u can feel the fire near ur legs & foots if jamm in traffic while summers.