(ET) New mower project

[Rod Hower <rodhower ameritech net>]

I think my gas push mower just crapped out.
When I started mowing it was 1/2" from full.
I parked it and smelled gas 20 minutes later
and it was dripping out the cap and completely
full.
I will convert it to electric with a BLDC motor
and control from work, 24Vdc.

What is the RPM of the mower blade on a standard
push mower?
Thanks,
Rod
P.S. I want the gas engine to be dead, it gives
me a legitimate excuse to convert to electric,
however I would still like to know how the gas volume
increases by at least 8 0z.  Did the crankcase crack?
I didn't hit anything, but it was running crappy.
Oil level was adequate and it was clean synthetic.