On the oil front, a multi grade oil is best for cold temps. I'm not sure where you live or what you are doing with the tractor. The below link may help. On the hard starting, verify that the choke is closing completely. It may be a simple cable adjustment.

Here is a link that might be useful: Briggs

Besides the thick oil issue, your tractor may only have a 3 AMP charging system.
IF you are doing a lot of cranking, it takes a lot of running to charge the battery back up. (10-12 hours for a fully discharged battery @ high speed)
You may simply be sinking faster than your are bailing.

Tom & Bill, Thanks, I will try your suggestions..

Tom, THANKS!! Throttle cable had slipped a little. I realigned it and it started on the first bump. Choke had been maybe half closed.