Normally the only thing electrical that is turned on via switches prior
to cranking the engine is the beacon. I killed the beacon...still, two
blades and no more. I then thought I'd kill the alt half of the master.
On the next start attempt, it fired right up. I don't remember if it was
after two or three blades. Maybe coincidence, maybe not having the t/c
gyro and everything else electrical that doesn't go through the avionics
master did the trick.

I know what I am going to type is counter-intuitive, but hear me out.

If you run into a battery that is not quite up to the job of getting enough
cranking speed, try the following procedure.

If it does not catch as quickly as it usually does, before you kill the
battery, stop-turn everything off, for two minutes. Look at your watch, or
timer. After the two is up, turn on your landing light, for one minute.
Again, time it. Turn everything off, and immediately try turning it over to
start. It will turn over faster than it did the first time.

The theory is that putting a relatively small continuous load on the battery
heats it up a bit, without taking too many amps out of it. The warm battery
will now be capable of putting out more amps than it could at the
temperature it was before.

Anyone else ever hear of that, or do this procedure before? It has worked
for me.
--
Jim in NC