ATC110 Stripped Spark Plug threads and Smokey Engine

[GreenChevelleSS]

New to the forum but have owned a 1984 Honda ATC110 for a few years now.
My 110 was ran into a pond and then set with water in the engine. When I got it I changed the oil, ran it and changed it agian...Did this a few times. Thing still ran great but smoked horribly. I ran it anyway then the plug fouled. I pulled it out and the carbon build up stripped the spark plug threads. Really ticked me off. Well I have it apart now rebuilding the top end. Everything looks great. I noticed a few tiny specs that looks like pitting in the cylinder but nothing that would cause it to smoke as bad as it does. Rings are not stuck or rusted either.
I did a slight hone on the cylinder and im gonna replace the valve seals and all the top end gaskets. Now I need to do something with the head. Heres my question, Should I helicoil the head and still use the 12MM spark plug or just retap the head for a 14MM sparkplug?

[DeePa]

just buy a new head off of ebay...they are cheap.

The exhaust header studs on my 200s stripped out, and i bought a new head for 13 shipped to my door on ebay. Helicoils cost more than that. If youre going to do the valves and seals anyways, why not just get a nice new head?

Mike

[GreenChevelleSS]

Ive been watching ebay for a good one but one has yet to come up. Ill keep watching anyway. Thanks

Danny