Got a minor issue.

When I try to start my 120y it won't fire untill key turned back to "on", that is, it will crank and crank untill you let go of the key, then it willl fire.

In most other cars i've driven, you crank, then the motor catches, then let go of the key.

Is it normal? If not, how to fix? Is it a problem with the starter motor?

There's a wire each side of the ballast resistor which both go back to your ignition barrel.

When 'cranking' the ballast resistor is shorted out to compensate for the voltage drop caused by the starter motor.

Sounds like the switch which shorts it out is fried (ie - your ignition switch).

Thanks tnPshow, ill czech it out.

It wouldn't hurt to check the wiring to the ballast resistor while you're at it too.