This one really baffles me.
Have a Sears electric start snowblower about 8 years old w/5hp
Tecumseh.
Did some basic maintenence ..changed oil, fresh gas, new plug, cleaned
carb

Idle screw set at 1 1/2 turns, bowl screw at 2 1/2 turns
primer squirts into carb ...tank and carb were spotless before
dissassembly

Had it running for about 20 min when weather was above freezing, but
required playing (did NOT start without help) with throttle butterfly
by depressing govenor link to get it started.
It ran at full speed and idle smoothly ...shut it off

Now that it got to 20 degrees ..can't get it to even puff ...not w/ or
w/o choke, not idle or full speed, not even with starter fluid in plug
hole or into carb, not with a spoonfull of gas into plug hole. Ran it
dry, warmed up cylinder with heat gun, let stand overnight...nothing!

Have a very bright spark, compression at 135psi, and some gas droplets
spits out carb while cranking

The only variable that I am NOT comfortable with, is the solid state
module, which is a pain to get to ...it it possible that the retaining
screws of that unit have loosened and it therefore is off timing??
the only artifact I see is that the bright spark seems to be too many
hits for the speed of the engine cranking ie firing too often, not
just once per rotation? But that might just be my inaccurate
perception.

Did an exhaustive google and came up with nothing.
I would be appreciative if anyone responds who has seen/solved this
problem.

TIA,
Stew Corman from sunny Endicott