Hydrolocked trimmer

[Weedwhacker]

So I have this trimmer that feels like it’s seized right up initially, but after pulling slowly a few times, and hearing liquid squishing through something, fuel leaks out the exhaust, she frees up, starts and runs like a champ.
My theory is that the carb is somehow leaking fuel into the crankcase and eventually filling up the combustion chamber.

Is this a thing that can happen?
What part in the carb would cause this to happen?
Did I cock it up, or did it autodestruct?

History:
Bolens Chinese grade trimmer I got for free.
Ran well for 2 seasons after I realigned epa carb adjustments to fix stall on acceleration.
I totally messed with it before trying to start it this season, so I don’t know if my idiot tinkering ruined it or if it got like that while it was in storage.

Messing with it this season:
Pulled spark arrestor for mo powah.
Pulled carb, gained full access to adjustments.
Couldn’t get it to run properly .
Lock up issue occurred overnight.
Removed plug, cleaned,
adjusted gap using finest eyeball measurements.
Found out motor spinning freely.
Reinstalled spark arrestor.
Tuned carb from scratch - 2 turns out H and L
Ran great.
Locked up after sitting overnight.

 

[DND 9000]

It can be a combination of pressure built up in the tank (that`s normal, because the tank vent opens only on vacuum) and a leaking inlet needle or stiff metering diaphragms that push always on the inlet control lever and open the needle. Check your carburetor, the needle seat and replace the diaphragms after a good cleaning (best ultrasonic cleaning). It can also be that dirt holds the needle open or that the needle tip is worn.