ST stinger Issue

Welcome to the forum...
Sounds to me like you need to lap your head and get a real gasket for starters... that epoxy is not good for your engine... especially what went into your engine as you bolted the head down tight, that stuff doesn't hold up to the heat these engines produce and if whatever amount of it squeezed out on the cylinder, the same amount squeezed out inside the combustion chamber, from there it melts and can smear down the cylinder wall and into your rings... not good...
If you got lucky there's no epoxy on your cylinder wall or trapped in the ring grooves.
With that said, the first thing I would do is take the head back off and check what the inside of the cylinder looks like, if there are any deep scratches or if there's any of that epoxy that dripped down the cylinder wall you'll need to get it out of there. Also if there are Any signs of it smearing on the cylinder wall you may need to pull the cylinder and check your rings. If the stuff got down in your rings or ring grooves you'll need a new set of rings, and if it scratched up the piston you'll need a new piston.
At least parts are cheap and you can replace everything for under $50 if it did get destroyed...

Hopefully there's no epoxy or residue inside the cylinder, but I would still recommend a new head gasket and to lap the head to ensure its flat and true, you can also lap the cylinder deck if it's not perfectly flat.
To lap the parts you née a few sheets of medium fine sandpaper and a very flat surface, most of us use a sheet of glass then lay the sandpaper face up on the glass, then lap the head by running it over the sandpaper in a circular or figure 8 pattern until the whole mating surface is flat and true with no imperfections. Finish the job with a finer sandpaper like 240 grit, you can do the lapping with 180 for a faster cut, then smooth it out with the 240. Clean the parts really well to ensure there's no sandpaper residue on the parts before reassembly. You can also lap the head or cylinder deck down in order to raise your compression ratio if your engine feels sluggish.

For your carb, there are 5 settings for the needle which controls the amount of fuel that goes into the engine at part throttle, placing the C clip higher on the needle leans it and lower riches it, you can experiment by moving the needle up or down one position at a time until it runs best.

Do all of what Dave said first, then search the forum for info on rejetting, and port matching. Fix your head, and pray for your cylinder, steel epoxy has no place on an aluminum head, my friend. That stuff is probably ten times harder than the China-luminum our motors are made of.
Fix your head go from there.