G'day Dave,
sounds like it's getting a drop of fuel or oil into the line. Your fix is
easy on the ground but won't help much when you need it.

Far be it for me to offer ideas on unauthorised mods, but a valve and a T
piece in the line to allow fresh (filtered cabin?) air to enter the line
while the engine is running and pulling vacuum (or boost if turbo?) should
let you flush the line at your leisure. Should only take a second or two. Or
a filter may be added to the beginning of the line. Something like a cheap
plastic inline fuel filter may work nicely for the filter to a cabin air
source as it will not be trying to cope with much pressure difference wgere
one at the engine end may have to handle that and high temp and vibration.

Other option that may help is a larger diameter tube that would require a
lot more fuel or oil to block.

Hope this helps,
Peter



"Dave Russell" wrote in message
om...
The manifold pressure gauge in my Super D is a pain. More acurately,
it's the line that connects it to the engine. Ten minutes of
aerobatics, and I can't get any kind of reliable reading; it just
sticks wherever.

It's easy to fix. A shot of air into the line (back toward the
engine, of course) and it's good to go, but this is becoming a real
bother. Can anyone tell me if there's a true fix for this, or am I
just doomed to blowing the line clean after every flight that I take
her inverted (i.e., as often as possible. :-)

Thanks,

-Dave Russell
8KCAB