Wrong spark plugs cause flooding?

I just bought a 87 Ski Nautique about 4 weeks ago, and have been sorting it out. After fixing most everything (man some people don't take care of their boats), today I changed the spark plugs. It was hard to start (just turned over and over)after it was fully warmed up and sat for a while. It seemed to be flooding, as I could hold the throttle fully open, and it would start, die, then run fine.
The PO had installed Champion RV8C plugs. They are much different looking from the Autolite 24. Short, with a recessed tip. That means a cold plug to me, yes?
It needed an impeller (had pieces of the old one in the thermostat housing almost blocking it), so I'm wondering if he tried a colder plug
since it was running hot? I guess! Why else would you run such a cold plug?
Runs fine now!

So putting in the correct plug totally fixed it then?

Oh, yes on points also, I will check them for gap and dwell.

I checked the idle screws, one was at 1 1/4 turns out, the other at 2 turns. I set them both at 1 1/2 turns per Holly's website. Seems to run and idle fine. No leakage visible after shutdown with the choke plate held open. Started right back up after 15 minutes.Hmm. Maybe the choke was sticking. I'll check that if it happens again.

Just a quick update. The choke wasn't opening completely even when if was completely warmed up (160). It was only closed maybe 1/5 of the way, but when I turned the choke housing, I had to go all the way past the last lean mark before it opened all the way. Now it starts right back up with a touch of throttle very eagerly, and revs better too.
I'm not sure the electric warm up feature is working even though it gets 13 volts when running, but as long as it's starting and running great I'll leave it alone. Don't fix it if it ain't broke!