When my engine gets hard to start I check the timing. If that is ok, I
replace the plugs. So far that has always done it. I switched to fine
wire plugs which last longer and don't seem to collect the lead at the
base. Hot starts are a bit problematical. I have heard that people do a
special shutdown procedure so they can start it. They flood it at
shutdown and cut it off with the key. That way there is fuel in the
cylinders for the start. You might try that.