I have a honda harmony hydrostatic 1101 its been in the shop 3 times the repairmen says first it had trash in the carb, I got it back it ran for an hour or so then cuts off again. Next he says the fuel lines collapsed so he changed those and it ran for a while then cut off again. If I let the mower sit for about two weeks it will run for almost an hour. It's a good rider when it's running I just don't know what could possibly be causing this.

Had the same problem when adding fresh gas. Non-ethanol.
I tried unscrewing the gas cap to LET vapors out.The cap should still be secured enough not to come off while mowing. Still works for me