Garry, I am just back from 3 weeks abroad so you may have sorted your
problem by now, but if not I would look carefully at the ignition circuits.
While still test flying my 914 mono 404 I found that I could not switch off.
The problem was intermittent and seemed to be worse when the engine was
thoroughly hot. The most helpful suggestions I got were: Firstly to get a
hand held radio with the squelch turned up so that you can hear igniton
interference, then switch off the mag circuits to see whether the
interference continued. For me it did confirming that I had a problem in the
mag grounding. Electrical testing of these circuits showed nothing wrong but
the second suggestion was from someone who had experienced the same problem
and cured it by hard wiring the mag leads where the push in bullet
connectors are situated just on top of the engine . I did this and have been
happily flying ever since without a hint of any further trouble. Cheers,
David Joyce G-XSDJ
----- Original Message -----
From: STOUT, GARRY V, CSFF2 <garrys@att.com>
Subject: Rotax 914 Dieseling
> Just recently, after 220 hours of operation, my Rotax 914 began
"dieseling" after shut down. Never happened before, but now does it every
time. I know that dieseling is caused by a "hot spot" somewhere in the
combustion chambers, but where and why escapes me. I've pulled the spark
plugs and aside from having some gray lead deposits on them, they look fine.
I plan to replace the plugs, but doubt that they are the cause.
Interestingly, the dieseling doesn't require a really hot engine. A few
days ago I started the engine and taxied 100 yards to the fuel pumps. At
shut down the engine dieseled.........and we know the engine hadn't yet even
warmed up. I've checked the mag grounding connections, and they work fine.
It is definitely a dieseling condition. Anyone out there experienced this
and what conclusions did you reach?
>
> Garry V. Stout
>
> District Manager, AT&T Business Services
> Phone: 813-878-3929 Fax 813-878-5651
>
> *****Please note new e-mail address******
>
>
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