Today's Message Index:
----------------------
1. 12:10 AM - Re: 914 mag check problem (Nigel Charles)
2. 03:55 AM - Mag drop on 914 (Mark Chetwynd-Talbot)
3. 05:21 AM - Re: Mag drop on 914 (Andy Draper)
4. 06:28 AM - Re: 914 mag check problem (DJA727@aol.com)
5. 06:33 AM - Re: Mag drop on 914 (DJA727@aol.com)
6. 06:42 AM - Re: 914 mag check problem (Fred Fillinger)
7. 07:42 AM - Re: 914 mag check problem (Jim Brown)
8. 12:47 PM - Re: 914 mag check problem (Jim Brown)
9. 06:57 PM - Re: 914 mag check problem (Ronald J. Parigoris)
10. 07:35 PM - Re: Mods needed for glider wings? (Joseph J. Like)
11. 10:46 PM - Re: 914 mag check problem (DJA727@aol.com)
12. 10:47 PM - Re: 914 mag check problem (DJA727@aol.com)
13. 10:50 PM - Re: 914 mag check problem (DJA727@aol.com)
14. 10:54 PM - Re: 914 mag check problem (DJA727@aol.com)
Message 1
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: "Nigel Charles" <nigelcharles@tiscali.co.uk>
>Two cylinders have a big EGT rise when on single mag - can't be traced to
any
component other than the plugs and wires - Plug #3 A circuit and #4 B
circuit.<
This sounds a little strange. When the mag drop is excessive you would
expect to find a cylinder with low rather than high EGT. I fitted 4 EGT
senders so that I could identify the rogue cylinder in the event of a failed
mag drop check. The only thing I can think of is that the rise indicates
that those cylinders are OK and working harder to overcome poor ignition in
one or both the other cylinders.
Is the mag drop as bad when the engine is not fully warmed up and without
the top cowl on? If so I would suggest that it is unlikely to be caused by
overheated electronics..
Your problem doesn't sound a typical Rotax problem. As for Lycomings, in the
past I have known of two cases which had difficult to solve mag drop
problems so they are not exempt.
Nigel Charles
Message 2
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--> Europa-List message posted by: "Mark Chetwynd-Talbot" <markt@avnet.co.uk>
This does not seem to be an isolated case. I have had a mag drop
'on the margin' for many months and I have now asked Andy at the
factory to see if he can come up with a cure. When I spoke to him
earlier this week he did mention that the factory demonstrator
was also suffering a similar problem! So, when anyone comes up
with a solution, please let everyone know about it!
Mark G-CHET
-----Original Message-----
--> Europa-List message posted by: DJA727@aol.com
Hello group,
I long for a good old reliable Lycoming engine! My 914 is now
failing the mag
check and everything I try has actually made it worse. I have
consulted with
Rotax and they have suggested several things - cleaning up the
connections at
the plug wires, swapping plugs too to bottom to see if the
situation reverses
(indicating a plug problem), changing the plugs to new.
The problem is I get a mag drop of 300 on circuit B and now 500
on circuit A.
At this point, with cleaned up wires, new plugs - it runs rough
on mags A
and B one at a time, with the large drop coming on A still. I now
cannot fly -
I
think it is even running rough with both mags on.
The latest suggestion is to check and clean up the ignition
ground bolt by
the electronic boxes. Then, it is to again check the carb synch -
THEN they need
to "see the engine", which can be a big problem where I live,
since I won't
fly it until I figure out what is wrong.
One other thing I can say is I don't think I ever had a very good
mag drop
since new. It was less than the limit of 300, but not by much
compared to what
most people are telling me.
Any suggestions out there besides replacing the engine with one
that a
control freak like me can adjust!
Dave
A227
Mini U2 (grounded)
---
Message 3
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| Subject: | Re: Mag drop on 914 |
--> Europa-List message posted by: "Andy Draper" <andy@europa-aircraft.com>
I should just qualify Mark's statement about the factory demonstrator having a
'similar problem' with regard to mag drops. The 914 engined demonstrator exhibits
a larger mag drop on one mag relative to the other but both are within limits
(300 rpm and 150 rpm difference). This is normal on the 914 as one mag runs
all upper plugs and the other all the lower plugs. Due to the geometry of
the cylinders, when one of the plugs ignites the mixture, it results in a different
flame path to that of the other, hence the difference in mag drop.
One of the factors that should not be ignored is to check the balance of the carburettors.
A mis-balance could result in one bank of cylinders or even one cylinder
causing the problem. We shall investigate this on Mark's engine before
anything else.
Regards
Andy Draper
>>> "Mark Chetwynd-Talbot" <markt@avnet.co.uk> 06/05/03 11:55am >>>
--> Europa-List message posted by: "Mark Chetwynd-Talbot" <markt@avnet.co.uk>
This does not seem to be an isolated case. I have had a mag drop
'on the margin' for many months and I have now asked Andy at the
factory to see if he can come up with a cure. When I spoke to him
earlier this week he did mention that the factory demonstrator
was also suffering a similar problem! So, when anyone comes up
with a solution, please let everyone know about it!
Mark G-CHET
-----Original Message-----
--> Europa-List message posted by: DJA727@aol.com
Hello group,
I long for a good old reliable Lycoming engine! My 914 is now
failing the mag
check and everything I try has actually made it worse. I have
consulted with
Rotax and they have suggested several things - cleaning up the
connections at
the plug wires, swapping plugs too to bottom to see if the
situation reverses
(indicating a plug problem), changing the plugs to new.
The problem is I get a mag drop of 300 on circuit B and now 500
on circuit A.
At this point, with cleaned up wires, new plugs - it runs rough
on mags A
and B one at a time, with the large drop coming on A still. I now
cannot fly -
I
think it is even running rough with both mags on.
The latest suggestion is to check and clean up the ignition
ground bolt by
the electronic boxes. Then, it is to again check the carb synch -
THEN they need
to "see the engine", which can be a big problem where I live,
since I won't
fly it until I figure out what is wrong.
One other thing I can say is I don't think I ever had a very good
mag drop
since new. It was less than the limit of 300, but not by much
compared to what
most people are telling me.
Any suggestions out there besides replacing the engine with one
that a
control freak like me can adjust!
Dave
A227
Mini U2 (grounded)
---
Message 4
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 12:11:03 AM Pacific Standard Time,
nigelcharles@tiscali.co.uk writes:
> This sounds a little strange. When the mag drop is excessive you would
> expect to find a cylinder with low rather than high EGT. I fitted 4 EGT
> senders so that I could identify the rogue cylinder in the event of a failed
> mag drop check. The only thing I can think of is that the rise indicates
> that those cylinders are OK and working harder to overcome poor ignition in
> one or both the other cylinders.
>
####The way I understand it is the single ignition causes a single flame
front, which delays the peak temperature and shortens the cooling time in the
cylinder, thus ejecting hotter gas into the exhaust. That is a normal thing for
Lycoming and continentals. I see about a 70 degree rise in my IK2000 on the twin
Comanche. All the cylinders rise in the Rotax, but two plugs rise about 150
degrees. I called Rotax again this morning and am going to check the resistance
of the plug wires and caps..........
> Is the mag drop as bad when the engine is not fully warmed up and without
> the top cowl on? If so I would suggest that it is unlikely to be caused by
> overheated electronics..
>
#######It seems worse when the engine is warmed up, but the cowl is off and
it still is bad when the engine is cool.......
> Your problem doesn't sound a typical Rotax problem. As for Lycomings, in
> the
> past I have known of two cases which had difficult to solve mag drop
> problems so they are not exempt.
>
########Grass is always greener, eh? I am sure I will be calmed down once I
solve this problem. After all, it did run fine for 65 hours!
Thanks,
Dave
Message 5
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| Subject: | Re: Mag drop on 914 |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 5:21:56 AM Pacific Standard Time,
andy@europa-aircraft.com writes:
>
> I should just qualify Mark's statement about the factory demonstrator having
> a 'similar problem' with regard to mag drops. The 914 engined demonstrator
> exhibits a larger mag drop on one mag relative to the other but both are
> within limits (300 rpm and 150 rpm difference). This is normal on the 914 as
one
> mag runs all upper plugs and the other all the lower plugs. Due to the
> geometry of the cylinders, when one of the plugs ignites the mixture, it results
> in a different flame path to that of the other, hence the difference in mag
> drop.
>
> One of the factors that should not be ignored is to check the balance of the
> carburettors. A mis-balance could result in one bank of cylinders or even
> one cylinder causing the problem. We shall investigate this on Mark's engine
> before anything else.
>
My carbs were off balance by quite a bit - my cable end securing nut came
loose (non Rotax Europa supplied) and after I did that, the engine ran much
smoother - except the mag drop and missing are even worse (I think it is
progressing down a bad path all by itself). I was getting a difference between
#3 and #4
at 2000 RPM of about 175 degrees - also a difference between 1 and 2. That
has evened out, but I am still getting very rough running on single mag
operation.
The timing is also different on the 914 between A and B. It is 22 and 26
degrees.
Dave
Message 6
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: Fred Fillinger <fillinger@ameritech.net>
> The timing is a fixed deal with pickups on the flywheel - no adjusting
> possible......
But a timing light may help identify a something defective. Have you
checked it? Also, an old spark plug can compare output of circuits A
and B by noting how wide a gap on the plug each will jump at crank speed
w/o plugs installed.
Regards,
Fred F.
Message 7
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: Jim Brown <acrojim@cfl.rr.com>
Dave;
In reading your comment that two cylinders have a rise in EGT of 140 degrees and
the other 6 cylinders have a rise of 40 degrees, leads me to suspect that the
mixture is to lean. If the mixture was to rich then you would have a drop in the
EGT's You can confirm this by doing a runup, then pull the plugs on the two
cylinders that rose 140 degrees and looking at the plugs.
In the maintenance manual look at the view of the exploded view of the carb. There
is a barrel that slides up and down in the center of the carb. there is a needle
valve in the center of the barrel. It has a circular clip around the top of the
needle valve, the clip is usually in the second ring from the top of the needle
valve, if this clip is moved down one notch it will richen up the mixture.
If you have any questions, please advise.
Jim Brown
DJA727@aol.com wrote:
> --> Europa-List message posted by: DJA727@aol.com
>
> In a message dated 6/4/2003 1:57:18 PM Pacific Standard Time, kheindl@msn.com
> writes:
>
> >
> > I don't really have a clue myself, but the instructor at a Katana Flying
> > School tells me that they have
> > ignition problems on very hot days. They use the bog standard 912, and they
> > say that the Ducati
> > ignition module tends to get too hot being right on top of the engine. They
> > would like to move
> > that box onto the firewall, but have their hands tied because it is a
> > certified engine.
> >
>
> I am doing these runs now with the cowing off, so I don't think the temp is
> the problem. I will be swapping plug wires tomorrow to see if I can isolate the
> trouble - the two cylinders I have a 150 degree rise vs about a 40 degree
> rise for the other 6 plugs.
>
> Dave
>
Message 8
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: Jim Brown <acrojim@cfl.rr.com>
Dave;
It would appear that I have given you an 8 cyl 914 in my posting to you this
morning.
Sorry about that!!!!!!!
Jim Brown
Jim Brown wrote:
> --> Europa-List message posted by: Jim Brown <acrojim@cfl.rr.com>
>
> Dave;
>
> In reading your comment that two cylinders have a rise in EGT of 140 degrees
and
> the other 6 cylinders have a rise of 40 degrees, leads me to suspect that the
> mixture is to lean. If the mixture was to rich then you would have a drop in
the
> EGT's You can confirm this by doing a runup, then pull the plugs on the two
> cylinders that rose 140 degrees and looking at the plugs.
>
> In the maintenance manual look at the view of the exploded view of the carb.
There
> is a barrel that slides up and down in the center of the carb. there is a needle
> valve in the center of the barrel. It has a circular clip around the top of the
> needle valve, the clip is usually in the second ring from the top of the needle
> valve, if this clip is moved down one notch it will richen up the mixture.
>
> If you have any questions, please advise.
>
> Jim Brown
>
> DJA727@aol.com wrote:
>
> > --> Europa-List message posted by: DJA727@aol.com
> >
> > In a message dated 6/4/2003 1:57:18 PM Pacific Standard Time, kheindl@msn.com
> > writes:
> >
> > >
> > > I don't really have a clue myself, but the instructor at a Katana Flying
> > > School tells me that they have
> > > ignition problems on very hot days. They use the bog standard 912, and they
> > > say that the Ducati
> > > ignition module tends to get too hot being right on top of the engine. They
> > > would like to move
> > > that box onto the firewall, but have their hands tied because it is a
> > > certified engine.
> > >
> >
> > I am doing these runs now with the cowing off, so I don't think the temp is
> > the problem. I will be swapping plug wires tomorrow to see if I can isolate
the
> > trouble - the two cylinders I have a 150 degree rise vs about a 40 degree
> > rise for the other 6 plugs.
> >
> > Dave
> >
>
Message 9
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: "Ronald J. Parigoris" <rparigor@suffolk.lib.ny.us>
Hello DJA727
> > Did you check timing?
> >
>
> The timing is a fixed deal with pickups on the flywheel - no adjusting
> possible......
I have a few early 1990 Volvo turbos. They use a speed sensor that senses magnets
on the flywheel. Had over the years on 2 different cars the sensors go flakey.
I
would call Lockwood Aviation ask for Phil in Florida. he seems to know the 914
in
and out. I think i have heard that if debris gets on the sensor or pick up it can
cause flakeyness. If easy pull sensors and inspect, inspect the flywheel for
debriis. If easy swap A and B sensors and see if trouble follows.
>
>
> > Could it be a carburation problem? I have a BMW R-100GS that uses Bing
> > constant
> > velocity carbs, and carb snot is a problem. For Hahas, try a mag check with
> > the
> > enriching circuit in rich mode and see if it makes a differance.
> >
>
> ##### I checked the balance of the carbs -- they needed balancing. I thought
> I had solved the problem. The run up is even worse with almost complete
> cutting out on the A mag.
>
I am not talking about carburator balance. I am talking about varnish from MoGas
plugging up passages and jets. On the R-100GS it is worst on the enriching
circuit, but saw signs in the main jet as well. General don't run high power
settings for long.
Did you try a mag check with the Enriching circuit on rich? (The Bings on BMW
don't use a choke, i am pretty sure the 914 uses the same enriching arrangement)
>
> #### Seems to be worse when cold. When I first started today, O thought is
> was extremely smooth -- the a lousy mag check again.
>
> Don't know ignition circuit. Is there a capacitor for RF noise somewhere in the
> circuit? If Easy perhaps you can switch the switch wires, to let A run B and
> vise versa. i don't know if ignition grounds? anyway eliminate the switch if
> you can.
If you did not replace the ignition wires see if you can swap A and B? Better yet
can you easily wire A input to B coil and vise versa?
Let us know how you make out
ron Parigoris
>
>
Message 10
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| Subject: | Re: Mods needed for glider wings? |
--> Europa-List message posted by: "Joseph J. Like" <josephlike@cox.net>
What cost? You lucky dog you.
Joe :)
Message 11
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 6:42:16 AM Pacific Standard Time,
fillinger@ameritech.net writes:
>
> But a timing light may help identify a something defective. Have you
> checked it? Also, an old spark plug can compare output of circuits A
> and B by noting how wide a gap on the plug each will jump at crank speed
> w/o plugs installed.
>
I plan to check the ignition with a timing light tomorrow -- looking for
ignition drop outs. I will also be running a compression check looking for
mechanical problems. I swapped ignition modules, a few plug wires, checked
gascolators for contamination and swapped cutout leads -- all changed absolutely
nothing
-- it still misses and runs rough.
Dave
Message 12
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 7:43:01 AM Pacific Standard Time,
acrojim@cfl.rr.com writes:
> In reading your comment that two cylinders have a rise in EGT of 140
> degrees and
> the other 6 cylinders have a rise of 40 degrees, leads me to suspect that
> the
> mixture is to lean. If the mixture was to rich then you would have a drop in
> the
> EGT's You can confirm this by doing a runup, then pull the plugs on the two
> cylinders that rose 140 degrees and looking at the plugs.
>
> In the maintenance manual look at the view of the exploded view of the carb.
> There
> is a barrel that slides up and down in the center of the carb. there is a
> needle
> valve in the center of the barrel. It has a circular clip around the top of
> the
> needle valve, the clip is usually in the second ring from the top of the
> needle
> valve, if this clip is moved down one notch it will richen up the mixture.
>
> If you have any questions, please advise.
>
> Jim Brown
Thank you,
I will look into that tomorrow when I go out and tackle the great engine
nemesis!
Dave
Message 13
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 12:48:02 PM Pacific Standard Time,
acrojim@cfl.rr.com writes:
>
> It would appear that I have given you an 8 cyl 914 in my posting to you
> this
> morning.
>
> Sorry about that!!!!!!!
>
I know what you mean!
thanks,
Dave
Message 14
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| Subject: | Re: 914 mag check problem |
--> Europa-List message posted by: DJA727@aol.com
In a message dated 6/5/2003 6:57:47 PM Pacific Standard Time,
rparigor@suffolk.lib.ny.us writes:
>
> If you did not replace the ignition wires see if you can swap A and B?
> Better yet
> can you easily wire A input to B coil and vise versa?
>
> Let us know how you make out
>
I did some swapping today to no avail. I also checked the resistance ion the
caps, wires and coils. Everything was to spec, of course.
Dave
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