Hi Byomarimba,
The first thing I like to do with a motor that won't run by putting fuel down the carby is to use a coil and spark plug
from a running motor as I have fitted coils many times from old engines and they don't work.
You could disconnect the kill switch wire from the coil just in case the switch is loose and earthing out intermittently.
50 PSI it should run no problem.
Cheers
Max.
