I have a 1950 3600 that sometimes does not like to start. Every now and then, I will step on the starter button and nothing happens and I can repeat this several times with the same results. Then it will catch and the starter will spin so in my case, I believe I have a problem with the switch on the starter. The other problem appears to be a bad wire to or from the ignition switch. Sometimes I have to put a jumper from the battery (cable on the starter) to the coil to get it to fire up.
Make sure your fan belt is tight enough.
