2008 4 stroke Tohatsu 8hp won't start. The flood!

Hello everyone first Q on the site.
I've got a little 8hp Tohatsu/mercury in a barrel that will turn and turn the starter for days won't kick once. The carburetor is spotless I've had it off 50× air compressor has done its job. Bowl gasket seals tight the float is perfect, not saturated, level not adjustable. inlet needle's perfect. It JUST had a kit. Pilot jet is set 1 5/8 turns. Choke butterfly works perfect. I'm moving the throttle butterfly by hand not the tiller handle. The fuel pump will shoot (non ethanol!!) gas 10 feet across the garage turning over. The gas line is hooked straight to the inlet barb of the fuel pump, no restriction from the inline filter or hose connection on the pan. No line leaks, air or gas.
I clamped the spark checker to the block, it's got spark. I popped the plugs out, wet with fuel on them. Attached the plug wires to the plugs, they spark. I don't have a compression gauge attachment for those small plugs so i just used my thumb. It was very easy to hold but apparently they only keep like 60lbs of pressure so that explains why it was so easy. The trigger coil doesn't advance with the throttle under the flywheel, it's bolted to the block. (Sparking anyway). It's not too much oil or got set down on the wrong side.
If I unhook the gas line and turn it over forever it will finally get lean enough to barely idle. The butterfly can wiggle the littlest bit open and quit, or just run out of gas. If i hook the line back up while it's running it floods out no matter what position the throttle is at. The cam belt hasn't jumped a tooth to mess up the valves.
When the engine was brought to me the negative battery cable had burnt shorted and fouled black under the insulation to no continuity. (Replaced them) But it was getting manually started and ran for awhile after the starter stopped working. Did this guy have salt water make connection pole to pole on the battery while he was full throttle and crash the computer box stuck in full timing advance? But wouldn't that have smoked the solenoid...
Did his regulator quit and start overcharging? It looks the same as the 40-50 yamaha 2stroke's but are the resistance specs the same?!
I've scanned the picture for quite awhile... Where's freakin Waldo!!!

OK, it sounds like you have an MFS8A3. Year is irrelevant on these.
The carb floats on these don't saturate; they are ultrasonically sealed capsules; full of air.
Apparently you have spark, proving out the exciter, pulser, siamese coil, and CD.
If the plugs are wet, the fuel is good, and you have good spark, you are clearly delivering too much fuel to run.

The 8/9.8 does not have decompression, so the thumb test doesn't tell you much.
No, the trigger does not advance; the advance curve is designed-in to the CD.
If you get it running on residual fuel in the carburetor, and then adding the fuel line causes flooding, that proves that something is wrong in the carb.
A lot of things could have wrecked the ground cable, including salt intrusion. No, the starter solenoid would have nothing to do with that. If the battery cables were shorted while running, the fuse would blow; I doubt it would have an effect on the CD.
The regulator/rectifier on these allows maybe 6 amps at WOT, so no, that would not burn an 8-gauge wire.

I would review the carburetor. Make 100% sure that the appropriate plug is in the nozzle bore, and that the needle is seating correctly.

Full info is in your trusty Factory service manual, available from any dealer, including me.

Incidentally, the carb for the MFS9.8A3 will bolt right on, and give you a lot more power.

Didn't think about the fuse keeping us safe from the battery. And I do know that solenoid's post would be black and welded from the + - connection sparking. I've had rectifiers go out and stators overcharge the system at full throttle. Trigger stayed at 26°, starter couldn't spin it fast enough to kick off . I only know this bc I had to replace 2 boxes and then finally the rectifier. It was just out of specs. I worried this little motor might've done the same.
I knew it was flooding over somehow so I went ahead with your advice to take the carb off for the 51st time. I looked up the carburetor diagram on Boats.net and started the checklist. But... I could not find a proper year Tohatsu model with this same carburetor top cover, they're all smooth flat on top. This has a big brass air-hose barb on top. I knew these motors were the same as Mercury so I looked up the carb diagram for an '08, 8hp merc. And there's my cover. Turns out this stickerless cowling belongs to a mercury! Well I bought the kit for a tohatsu, bc it's 75% cheaper, and the only thing different is the carb cover gasket
Tohatsu: 3V1031820
Mercury: 855541003
There's an extra hole stamped right under where the barb is on the mercury gaskets and no extra hole on the Tohatsu gaskets, because there's no air hose barb, of course. I stamped a 1/4" hole where it goes with the gasket punch. It leaned up and started running. I went inside (to celebrate) before I ever dialed it in. But it idled awhile with a little extra throttle, jumped without bog and ran in gear. I'll check the pilot in the morning and see if I can get the idle down and right. I think this did it though. I'll confirm tomorrow
Thanks Paul I probably wouldn't have studied those diagrams all day and finally noticed that gasket till quite a few more hours of thinking