On 2010-08-21, SF Man wrote:

No. I could easily hold my thumb on the hole. It puffed like the way you
would blow a fly off your wrist.

Before you give up, remove the spark plug, squirt or pour some motor
oil into the cylinder, and cycle the engine a few times, rotating it
around so the oil gets everywhere in the cylinder coating rings and
cyl wall, then press your thumb down hard on the open spark plug hole.
Make sure you have the hrottle wide open, then try again.

Of course, it's only a 40cc engine ... so I'm not sure how much compression
it should have.

Size of the cylinder has no bearing on amount of pressure. A two
stroke engine needs a minimum amount of compression pressure to get
good combustion. As an old 2-stroke motorcycle mechanic, I can assure
you that "minimum amount" will blow past your finger/thumb no matter
the cyl size or how hard you resist. It's truest "rule of thumb"
ever.

nb