Problem with Robinson R22 Beta MAP.

[riddle1978]

Check A my Robinson R22 Beta this morning and everything was ok as usual.
But by the time i had pushed it out onto the Heli pad and got in to it for start-up i noticed the Manifold Pressure guage was reading 28"Hg instead of the usual reading of 30"Hg which it was showing when i first checked it?
Would i have a faulty guage or a leak in the line or could there be something else wrong, and would it be safe to continue flying?

[Billywizz]

The MAP gauge should be reading static air pressure before you turn the engine on.
What was the QNH at the time?
28" mercury = 948.2mb

[riddle1978]

My QNH was 983mb, have the helicopter over 2 years and have never had a deviation in map as large as this before?

[Efirmovich]

With the engine not running any holes in pipes or such like will not make any difference, it should still read correctly on the lounge coffee table............

E.

[lelebebbel]

What is your field altitude?

QNH 983mb (29") and air pressure 948mb (=28" MAP, engine OFF) is correct if you are at ~1,000ft MSL

[riddle1978]

Im at 600ft asl.

Today the QNH is 976mb and the MAP is still showing 28".

[topendtorque]

check the rubber seal betwixt glass and instrument case, if it has buckled inwards then likely he needle is being caught by it.