want to put a kick starter on my 82 kz750 ltd

dos anyone know if the kick starter of a kz650 will work covers look the same if my baterys even 2 volts low it will not start my bike unless i time it right or pop it it starts right up

2 volts low is low. The bike needs a good battery to run right.
I prefer checking the battery w a digital multimeter.
If applicable, make sure the electrolyte level is correct (add distilled water - not tap water or acid).

High beam test. Charge the battery, then disconnect the charger. You should have at least 12.6 VDC but the voltage will probably be higher ~13.1+. Turn on the high beam (engine off). The voltage will drop. A good battery will drop to ~12.2 VDC but ~11.85 is okay. If it drops to 11 VDC, the battery may need replacing. If it drops to 10 VDC, the battery is probably shot. The high beam test removes the surface charge & gives a better indication of the deep charge, or something like that. The voltages are the numbers I use. There may be a more accurate set of voltages on the internet somewhere.

PS: a kick starter can be installed, but it is a lot of work, as you have to split the cases.

Agreeed. Two volts low is a dead battery.

I have installed the kick starter into a 750e motor it will work and is work.

I guess you could also just swap the motor with another one with kick starter already on it, but then again, a lot of work, only worth it if you really need to--engine failure.
c