I have the answer, but I don't understand why. Maybe you can help.
My 240 wouldn't start. I turned on the lights and checked the battery voltage (ok). I turned the key and heard the buzz of the fuel pump, but no "click, click" of the starter. I thought the starter was bad. I whacked it a couple of times and it started but only once (this happened three times). Meanwhile, I noticed that I knocked loose a wire and that the alternator only had one wire attached to it (positive terminal). Presumably, the wire was the negative lead to the alternator, so I reconnected it to the alternator, though not securely. I replaced the starter and had the old starter tested (it was fine). I cranked the ignition with the new starter, and nothing happened. I reconnected the wire and everything started up well. Why does a loose negative alternator lead prevent the starter from working?