Today's Message Index:
----------------------
1. 11:20 AM - Re: Ignition problem (mikeperkins)
2. 03:28 PM - Re: Re: Ignition problem (Noel Loveys)
3. 03:58 PM - Re: Re: Ignition problem (Dave)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Ignition problem |
I've not seen this exact problem, but I have a few thoughts based on the assumption
that the system once did not perform this way.
The 582 has the Ducati ignition system, meaning it's an electronic version where
the coils and the tach are operated by a module. Here are the possibilities
as I see them:
1) There is an open ground either at the ignition switch, ignition module, or the
tach. (Missing grounds can make very strange things happen.)
2) There is a short between one of the ignition cutoff wires ("mag" leads) and
the tach lead.
3) The ignition module is bad.
Here's what I'd do to troubleshoot.
With all leads removed from the ignition switch, check that it works properly with
an ohmmeter (that the keyswitch connects the right terminals in the right
positions, and also not in the wrong positions.) Also check for a short between
the both mag leads and the tach wire.
If everything seems ok to this point, or you can't test the switch easily, still
leave the switch disconnected and hookup jumpers that can allow you to test-run
the engine without the ignition switch - so you can start the engine and do
an individual "mag check" with the engine running. See if the tach behaves.
If the tach still misbehaves, then it's likely a bad ground somewhere on the ignition
module or (ugh) a bad ignition module.
I'm sure you see the basic idea - check for problems with the switch and the wiring.
. . . and then run the engine isolated from as much of the aircraft wiring
as possible to see if the Ducati ignition module is good or bad.
Hope this helps.
Mike Perkins
Kitfox Model I (1994)
532 / GSC prop
TC and FA
Electronic Engineer
--------
Mike Perkins
EAA TC/FA
Havana, Illinois
Model I, 532, B gearbox, GSC prop
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=369069#369069
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Ignition problem |
It's been a while since I've looked at the schematic for the 582 but if I
remember correctly the tachometer does NOT go through the ignition module
but operates from a separate coil in the magneto. There have been problems
with the Westach tachometer seeing either too much or not enough voltage on
the tach coil. My advice is what I did and get a TinyTach just be sure to
wrap BOTH wires to either cylinder so it will read with either mag coil
turned off.
Noel
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of mikeperkins
Sent: March 21, 2012 3:50 PM
Subject: Kitfox-List: Re: Ignition problem
<michael.perkins@rauland.com>
I've not seen this exact problem, but I have a few thoughts based on the
assumption that the system once did not perform this way.
The 582 has the Ducati ignition system, meaning it's an electronic version
where the coils and the tach are operated by a module. Here are the
possibilities as I see them:
1) There is an open ground either at the ignition switch, ignition module,
or the tach. (Missing grounds can make very strange things happen.)
2) There is a short between one of the ignition cutoff wires ("mag" leads)
and the tach lead.
3) The ignition module is bad.
Here's what I'd do to troubleshoot.
With all leads removed from the ignition switch, check that it works
properly with an ohmmeter (that the keyswitch connects the right terminals
in the right positions, and also not in the wrong positions.) Also check for
a short between the both mag leads and the tach wire.
If everything seems ok to this point, or you can't test the switch easily,
still leave the switch disconnected and hookup jumpers that can allow you to
test-run the engine without the ignition switch - so you can start the
engine and do an individual "mag check" with the engine running. See if the
tach behaves.
If the tach still misbehaves, then it's likely a bad ground somewhere on the
ignition module or (ugh) a bad ignition module.
I'm sure you see the basic idea - check for problems with the switch and the
wiring. . . . and then run the engine isolated from as much of the aircraft
wiring as possible to see if the Ducati ignition module is good or bad.
Hope this helps.
Mike Perkins
Kitfox Model I (1994)
532 / GSC prop
TC and FA
Electronic Engineer
--------
Mike Perkins
EAA TC/FA
Havana, Illinois
Model I, 532, B gearbox, GSC prop
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=369069#369069
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Ignition problem |
There are a fair number of people experiencing this issue if you use the
proper terms in a Google search. To save you the effort Mike Stratford has
written a number of informative articles on the Rotax engine, always the
first place to look when you have a question IMO. # 49 addresses just this
issue.
http://www.800-airwolf.com/pdffiles/ARTICLES/Part%2049%20-%204%20page.pdf
here is the paragraph quoted from the article.
Why does my Tach go Crazy During a Mag Check?: Before we get started I have
to answer one of the most common questions about a
Ducati System. Many operators panic when their electronic Tach does not
respond as expected during a Mag check. Knowing how the circuit works one
can actually expect
to get strange Tach readings. The gray wire is connected to a common pair in
the ignition poles with the circuit being completed to thru a ground wire.
This produces the 6
pulses per revolution the Tach is reading. During a Mag check the ignition
voltage is dumped to ground thru a shorting cable (wire #8 in figure #2)
killing one side of the dual
ignition. The pulse or wave can come up the ground wire confusing the Tach
as to the actual pulses being received. Moving the ground wire around will
likely produce mixed
results. Obviously a Mag check will not produce the standard GA rpm drop
many pilots come to expect and there is little you can do to change that. It
is best to just listen for
the rpm drop and ignore the tach. END OF QUOTE
T
he upshot of the paragraph is don't worry about it. Good luck!
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|