Engine stoppage during idle

On Tue, 19 Sep 2006 05:36:55 +0100, Peter
wrote:

IO-540-C4, Socata TB20

Just got this today. Landed, taxied off the runway, and before doing
the post-landing procedure (ie, with the mixture on full rich and the
fuel pump still running) noticed the revs to be very low, c. 500 and
then unsuprisingly the engine stopped.

Initially I suspected the idle setting had got moved. Did a start (hot
start, the usual lots of cranking) and all was fine. Idle is perfect
at 700rpm, just the way it was set up by a very good Socata engineer a
couple of years ago. Mag checks fine, EDM700 fine.

snip

RPM rise when pulling the mixture to ICO? Cold vs. hot?

If it's hard to determine @ 700, try it closer to 1000.

You may not be able to see it on the tach, but you should be able to
hear a slight RPM increase as the mixture is pulled. No rise, idle
mixture is too lean-more than a little (25-50 RPM), idle mixture too
rich.

Ensure that the crank on the servo is positively contacting the idle
rpm stop before the throttle control reaches the end of its travel...

TC

On Tue, 19 Sep 2006 21:45:02 GMT, wrote:

On Tue, 19 Sep 2006 05:36:55 +0100, Peter
wrote:

IO-540-C4, Socata TB20

Just got this today. Landed, taxied off the runway, and before doing
the post-landing procedure (ie, with the mixture on full rich and the
fuel pump still running) noticed the revs to be very low, c. 500 and
then unsuprisingly the engine stopped.

Initially I suspected the idle setting had got moved. Did a start (hot
start, the usual lots of cranking) and all was fine. Idle is perfect
at 700rpm, just the way it was set up by a very good Socata engineer a
couple of years ago. Mag checks fine, EDM700 fine.

snip

RPM rise when pulling the mixture to ICO? Cold vs. hot?

If it's hard to determine @ 700, try it closer to 1000.

The Deb idle is 500, the mechanic wanted to see a slight rise when
slowly pulling the mix to cut off.



You may not be able to see it on the tach, but you should be able to
hear a slight RPM increase as the mixture is pulled. No rise, idle
mixture is too lean-more than a little (25-50 RPM), idle mixture too
rich.

Ensure that the crank on the servo is positively contacting the idle
rpm stop before the throttle control reaches the end of its travel...

TC
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com