Intake Manifold vacuum @ hot idle

[iain]

What should the intake manifold value be at hot idle ? at 2k rpm ? at
WOT snap peaks ? [ wide open throttle ] .
i know good and bad values for 4 6 8 cyclinder engines ... but a 2
cylinder ? not a clue
thanks .

[Steve]

My dad always said any engine should pull 15" vacuum at idle, but I
could never get more than 7 - 10 inches with a vacuum gauge. I
tapped into the int manif and glued in a brass tube. A restrictor
might help. It may be due to the single carb and the valving of the
engine.
Miles