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Question about High EGTs on a 912

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lgold(at)quantum-associat
Guest

Posted: Tue Apr 27, 2010 8:53 pm Post subject: Question about High EGTs on a 912

After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100 RPM yesterday I noticed an EGT problem. Toward the end of the flight, with OAT about 65F at 2000’, the EGTs started creeping up to 1620F (the maximum allowed temp) on one exhaust and about 1590F on the other. It dropped when I reduced RPM to 4000 or raised it to 5500RPM.   

When I noticed this, I looked around. After getting my head out of a clouds, I also noticed the engine was running on a single mag. I am hoping that this was the cause of the overheating, although I don’t understand why this should be so.  

It’s going to be raining here (in N. California) for a few days.  Since I can’t fly to check out if running on both mags will bring the EGTs down, I was wondering if anyone in Rotax land had an opinion about whether running on a single mag could causing the high EGTs.  If you don’t think running on a single mag caused the problem, and you have seen this before, I could use advice as to how to proceed before tearing the carbs apart.  

When I can fly again, I’ll report if the mag issue was the culprit here.   

Les       

   

       [quote][b]

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Wed Apr 28, 2010 3:40 am Post subject: Question about High EGTs on a 912

Just a thought, but with only one mag operating you're dumping some raw gas

out into the exhaust that burns right over your EGT sensors. That would

account for the higher EGT's.



Rick Girard



On Tue, Apr 27, 2010 at 11:51 PM, Les Goldner

<lgold(at)quantum-associates.com>wrote:



[quote]  After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100

 RPM yesterday I noticed an EGT problem. Toward the end of the flight, with

 OAT about 65F at 2000’, the EGTs started creeping up to 1620F (the maximum

 allowed temp) on one exhaust and about 1590F on the other. It dropped when I

 reduced RPM to 4000 or raised it to 5500RPM.



 When I noticed this, I looked around. After getting my head out of a

 clouds, I also noticed the engine was running on a single mag. I am hoping

 that this was the cause of the overheating, although I don’t understand why

 this should be so.



 It’s going to be raining here (in N. California) for a few days.  Since I

 can’t fly to check out if running on both mags will bring the EGTs down, I

 was wondering if anyone in Rotax land had an opinion about whether running

 on a single mag could causing the high EGTs.  If you don’t think running on

 a single mag caused the problem, and you have seen this before, I could use

 advice as to how to proceed before tearing the carbs apart.



 When I can fly again, I’ll report if the mag issue was the culprit here

_________________
The smallest miracle right in front of you is enough to make you happy....

flyadive(at)gmail.com
Guest

Posted: Wed Apr 28, 2010 6:37 am Post subject: Question about High EGTs on a 912

Les:



Rich hit the nail on the head.  Unburnt gas burning in the exhaust

pipes will increase your EGT.



Prove it to yourself... Fly with ans without a Mag on.

Barry



On Wed, Apr 28, 2010 at 12:51 AM, Les Goldner

<lgold(at)quantum-associates.com> wrote:

 	  Quote: 	
		   After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100 RPM

 yesterday I noticed an EGT problem. Toward the end of the flight, with OAT

 about 65F at 2000’, the EGTs started creeping up to 1620F (the maximum

 allowed temp) on one exhaust and about 1590F on the other. It dropped when I

 reduced RPM to 4000 or raised it to 5500RPM.



 When I noticed this, I looked around. After getting my head out of a clouds,

 I also noticed the engine was running on a single mag. I am hoping that this

 was the cause of the overheating, although I don’t understand why this

 should be so.



 It’s going to be raining here (in N. California) for a few days.  Since I

 can’t fly to check out if running on both mags will bring the EGTs down, I

 was wondering if anyone in Rotax land had an opinion about whether running

 on a single mag could causing the high EGTs.  If you don’t think running on

 a single mag caused the problem, and you have seen this before, I could use

 advice as to how to proceed before tearing the carbs apart.



 When I can fly again, I’ll report if the mag issue was the culprit here.



 Les

lgold(at)quantum-associat
Guest

Posted: Wed Apr 28, 2010 8:29 am Post subject: Question about High EGTs on a 912

Barry and Rick,

I hope you guys are right. I'll let you know in a few days when I can fly

again. 

FYI, In my 2-stroke Rotax 503, extra gas (i.e., rich burn) decreases temps,

but this I a little different situation. 

Les



--

sdemeyer

Joined: 31 Jul 2009
Posts: 45

Posted: Wed Apr 28, 2010 8:50 am Post subject: Question about High EGTs on a 912

Hmm, I don't understand how there could be much, if any unburnt gas in the exhaust pipe while running on one ignition module. It is my understanding that both plugs fire at the same time on a 912. I would think you would need a lot of raw fuel to make EGT increase that much. How could there be enough unburnt gas to make a difference? I would suspect something else like a plugged jet or intake vacuum leak. 



I know I've had many issues with the carb sockets coming apart. This substantially increased my EGT.



Scott



--- On Wed, 4/28/10, FLYaDIVE <flyadive(at)gmail.com> wrote:

[quote]

From: FLYaDIVE <flyadive(at)gmail.com>

Subject: Re: RotaxEngines-List: Question about High EGTs on a 912

To:  rotaxengines-list(at)matronics.com

Date: Wednesday, April 28, 2010, 7:23 AM



--> RotaxEngines-List message posted by: FLYaDIVE <[url=/mc/compose?to=flyadive(at)gmail.com]flyadive(at)gmail.com[/url]>



Les:



Rich hit the nail on the head.  Unburnt gas burning in the exhaust

pipes will increase your EGT.



Prove it to yourself... Fly with ans without a Mag on.

Barry



On Wed, Apr 28, 2010 at 12:51 AM, Les Goldner

<[url=/mc/compose?to=lgold(at)quantum-associates.com]lgold(at)quantum-associates.com[/url]> wrote:

 	  Quote: 	
		   After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100 RPM

 yesterday I noticed an EGT problem. Toward the end of the flight, with OAT

 about 65F at 2000â€™, the EGTs started creeping up to 1620F (the maximum

 allowed temp) on one exhaust and  about 1590F on the other. It dropped when I

 reduced RPM to 4000 or raised it to 5500RPM.



 When I noticed this, I looked around. After getting my head out of a clouds,

 I also noticed the engine was running on a single mag. I am hoping that this

 was the cause of the overheating, although I donâ€™t understand why this

 should be so.



 Itâ€™s going to be raining here (in N. California) for a few days.  Since I

 canâ€™t fly to check out if running on both mags will bring the EGTs down, I

 was wondering if anyone in Rotax land had an opinion about whether running

 on a single mag could causing the high EGTs.  If you donâ€™t think running on

 a single mag caused the problem, and you have seen this before, I could use

 advice as to how to proceed before tearing the carbs apart.



 When I can fly again, Iâ€™ll report if the mag issue was the  culprit here.



 Les






	


http://www.matronics.com/contribution[/url] [quote][b]

flyadive(at)gmail.com
Guest

Posted: Wed Apr 28, 2010 9:55 am Post subject: Question about High EGTs on a 912

Hi Scott:

 With a dual Mag system you are correct... Both Mags fire at the same time.  Or SHOULD!

 If because of timing or poor connection they do not there will probably be a poor burn in the cylinder and incomplete burnt fuel will be pushed out the exhause pipes.

 The average EGT is between 1300 to 1400 F.  So jumping from 1400 to 1600 is only a 200 F jump.  That is not much - But it is a temp we do not want to see.

 Cars have experimented with CATALYTIC CONVERTS to burn the incomplete burnt fuel and they get quite hot.  Of course that is also because of the catalytic element.  And burning fuel in the exhaust system with spark plugs and nichrome wire have also been tried.  All this to reduce out exhaust emissions.

 Barry

 On Wed, Apr 28, 2010 at 12:27 PM, Scott DeMeyer <scottsr1100rt(at)yahoo.com (scottsr1100rt(at)yahoo.com)> wrote:

 [quote]    Hmm, I don't understand how there could be much, if any unburnt gas in the exhaust pipe while running on one ignition module. It is my understanding that both plugs fire at the same time on a 912. I would think you would need a lot of raw fuel to make EGT increase that much. How could there be enough unburnt gas to make a difference? I would suspect something else like a plugged jet or intake vacuum leak. 

I know I've had many issues with the carb sockets coming apart. This substantially increased my EGT.

Scott

--- On Wed, 4/28/10, FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)> wrote:

   	  Quote: 	

From: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>  

Subject: Re: Question about High EGTs on a 912

To: rotaxengines-list(at)matronics.com (rotaxengines-list(at)matronics.com)

Date: Wednesday, April 28, 2010, 7:23 AM

 --> RotaxEngines-List message posted by: FLYaDIVE <flyadive(at)gmail.com>

Les:

Rich hit the nail on the head.  Unburnt gas burning in the exhaust

 pipes will increase your EGT.

Prove it to yourself... Fly with ans without a Mag on.

Barry

On Wed, Apr 28, 2010 at 12:51 AM, Les Goldner

<lgold(at)quantum-associates.com> wrote:

 > After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100 RPM

 	  Quote: 	
		   yesterday I noticed an EGT problem. Toward the end of the flight, with OAT

 about 65F at 2000’, the EGTs started creeping up to 1620F (the maximum

 > allowed temp) on one exhaust and about 1590F on the other. It dropped when I

 	  Quote: 	
		   reduced RPM to 4000 or raised it to 5500RPM.

 When I noticed this, I looked around. After getting my head out of a clouds,

 > I also noticed the engine was running on a single mag. I am hoping that this

 	  Quote: 	
		   was the cause of the overheating, although I don’t understand why this

 should be so.

 It’s going to be raining here (in N. California) for a few days.  Since I

 > can’t fly to check out if running on both mags will bring the EGTs down, I

 	  Quote: 	
		   was wondering if anyone in Rotax land had an opinion about whether running

 on a single mag could causing the high EGTs.  If you don’t think running on

 > a single mag caused the problem, and you have seen this before, I could use

 	  Quote: 	
		   advice as to how to proceed before tearing the carbs apart.

 When I can fly again, I’ll report if the mag issue was the culprit here.

 >

 	  Quote: 	
		   Les

http://www.matronics.com/Navigator?RotaxEngines-List   --> http://www.matronics.com/contribution

  	  Quote: 	

ist" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List

ttp://forums.matronics.com

_blank">http://www.matronics.com/contribution

[b]

Ollie Washburn

Joined: 10 Jan 2006
Posts: 56
Location: Central Florida

Posted: Thu Apr 29, 2010 4:49 am Post subject: Question about High EGTs on a 912

EGT will tell you many things and everyone should read up up on the

telltale signs and yes a failed mag or failed plug will show a high EGT on

all cyls for mag and single cyl for failed plug. Electronics International

used to and probable still does give a lot of information in their manual.

You may be able to get it on line and if so it is worth the read.

On Wed, Apr 28, 2010 at 1:13 PM, FLYaDIVE <flyadive(at)gmail.com> wrote:



[quote] Hi Scott:



 With a dual Mag system you are correct... Both Mags fire at the same time

_________________
Ollie RV6-A & Rans S7S
Central FL

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Thu Apr 29, 2010 4:50 am Post subject: Question about High EGTs on a 912

Just a contrarian view.  LOP which is less fuel equates to higher EGTs till you are on the backside of the Combustion/EGT curve.  Excess gas (including unburned) reduce the temps hence why so many run ROP to save the exhaust valves and lower EGTs.  I will enjoy your explanation of the opposite conclusion.



John Cox



--

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Thu Apr 29, 2010 1:29 pm Post subject: Question about High EGTs on a 912

John, Lean of Peak IS the backside of the combustion curve and as you say EGT cools. EGT is measured anywhere from 1" to 4" from the exhaust port not at the exhaust valve so while you can cool the valve with excess fuel you will drive up EGT doing it. 



Rick Girard



On Wed, Apr 28, 2010 at 2:14 PM, John Cox <johnwcox(at)pacificnw.com (johnwcox(at)pacificnw.com)> wrote:

[quote] --> RotaxEngines-List message posted by: "John Cox" <johnwcox(at)pacificnw.com (johnwcox(at)pacificnw.com)>

 

 Just a contrarian view.  LOP which is less fuel equates to higher EGTs till you are on the backside of the Combustion/EGT curve.  Excess gas (including unburned) reduce the temps hence why so many run ROP to save the exhaust valves and lower EGTs.  I will enjoy your explanation of the opposite conclusion.

  

 John Cox

 

 --

_________________
The smallest miracle right in front of you is enough to make you happy....

JimT

Joined: 27 Feb 2006
Posts: 22
Location: Auburn, ME

Posted: Thu Apr 29, 2010 2:53 pm Post subject: Question about High EGTs on a 912

yeah but:

 

 if you lean far enough combustion becomes incomplete, so the gas  is still burning as the exhaust vavle opens, resulting in a second, higher  EGT.   I learned of this when running the leaning test per GAMI.  I was alarmed when one cylinder when very high quite rapidly during the lean test.   The engine was still running smooth as the  5 other cylinders ( Cherokee 6 , IO 550,  , my  certified airplane).   The gami rep said there will be a second peak, sometimes.   The sent a new injector and now  the peak is  the same for all cylinders.

 

  

   

 

   

 

  --

flyadive(at)gmail.com
Guest

Posted: Thu Apr 29, 2010 3:03 pm Post subject: Question about High EGTs on a 912

John:



ROP & LOP ...

When I took my Complex Training in a Fuel Injected engine I was taught

to Lean - LOP.

I was also told that LOP is ONLY for FUEL INJECTED engines.

All the planes I fly are corroborated so I have never tried to lean LOP.

How much of a fuel savings is it?  I have no idea.  But, I would

venture to guess in 100 Hrs a year of flying your saving would be 1/4

a GPH so 100 Hrs = 25 Gal... BUT!  How much of that 100 Hrs are you in

cruse?



ROP - Now running ROP is a Carburetor issue.  And that is mainly

because when leaning not ALL cylinder have the same fuel air ratio. So

they do not all reach the same point at the same time.  You lean until

the engine runs rough and then ritchen a bit... How much is a bit?

That will depend on what YOU feel comfortable with.  There is NO real

scientific information to go by.  It is after all a fishing

expedition.  You drop your line in the water and hope you have the

right hook, line, bait and depth.  EGT is ONLY an indication and is

variable with probe location, type of probe, air flow around the

engine and calibration of the unit.  Probably a few more that I am

missing.



In the long and short of it... We fly for fun and at the end of a year

or even ten years will $200 mean that much?  Especially when compared

to an engine overhaul.



Barry



On Wed, Apr 28, 2010 at 3:14 PM, John Cox <johnwcox(at)pacificnw.com> wrote:

[quote] 



 Just a contrarian view.  LOP which is less fuel equates to higher EGTs till you are on the backside of the Combustion/EGT curve.  Excess gas (including unburned) reduce the temps hence why so many run ROP to save the exhaust valves and lower EGTs.  I will enjoy your explanation of the opposite conclusion.



 John Cox



 --

Ollie Washburn

Joined: 10 Jan 2006
Posts: 56
Location: Central Florida

Posted: Thu Apr 29, 2010 3:13 pm Post subject: Question about High EGTs on a 912

 John, you are talking about two different scenarios, normal cyl and one with plug not firing. 





On Wed, Apr 28, 2010 at 3:14 PM, John Cox <johnwcox(at)pacificnw.com (johnwcox(at)pacificnw.com)> wrote:

 [quote]--> RotaxEngines-List message posted by: "John Cox" <johnwcox(at)pacificnw.com (johnwcox(at)pacificnw.com)>

  

 Just a contrarian view.  LOP which is less fuel equates to higher EGTs till you are on the backside of the Combustion/EGT curve.  Excess gas (including unburned) reduce the temps hence why so many run ROP to save the exhaust valves and lower EGTs.  I will enjoy your explanation of the opposite conclusion.

  

 John Cox

 

 --

_________________
Ollie RV6-A & Rans S7S
Central FL

flyadive(at)gmail.com
Guest

Posted: Thu Apr 29, 2010 6:13 pm Post subject: Question about High EGTs on a 912

Yea, but!!



What is the point that you are trying to make?



That you had the wrong or bad injector and that cylinder was running

richer than the others?



That is all that was happening.  Running too rich on one cylinder.

Lower the amount of fuel in the rich cylinder, so all the cylinders

will peak at OR close to the same time.



As for: "so the gas  is still burning as the exhaust valve opens" -

That is always true.  The exhaust valve is OPEN way before the burn

time of the fuel has been completed.  There is a huge overlap of

ignition and valve opening.



Barry



On Thu, Apr 29, 2010 at 6:33 PM,  <jtortho(at)aol.com> wrote:

[quote]

 yeah but:



 if you lean far enough combustion becomes incomplete, so the gas  is still

 burning as the exhaust vavle opens, resulting in a second, higher  EGT.   I

 learned of this when running the leaning test per GAMI.  I was alarmed when

 one cylinder when very high quite rapidly during the lean test.   The engine

 was still running smooth as the  5 other cylinders ( Cherokee 6 , IO 550,  ,

 my  certified airplane).   The gami rep said there will be a second peak,

 sometimes.   The sent a new injector and now  the peak is  the same for all

 cylinders.

 --

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Thu Apr 29, 2010 8:47 pm Post subject: Question about High EGTs on a 912

Generally both mags should fire at the same time but there are exceptions...  The C-172 used to have offset mag timing,   Several Ads were out to change the timing and then change it back.  I’m not sure where it is now and of course there is the question of impulse coupling where one mag will be timing retarded below 500 rpm for starting.  Usually those engines are started on one mag then when it starts the second mag is turned on.  

When catalytic convertors were first installed on cars some people mistakenly fuelled up with leaded fuel.  The catalytic converters, brand new, would try harder and harder to burn off the lead deposits.  This would turn the convertors white hot and some melted the frames of their cars.  Shortly afterward an insert was put into the gas filler to not allow a leaded nozzle to put gas into an unleaded fuel vehicle.  

Just a bit of trivia.  

Noel  

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of FLYaDIVE

 Sent: April 28, 2010 2:44 PM

 To: rotaxengines-list(at)matronics.com

 Subject: Re: Question about High EGTs on a 912  

Hi Scott:  

With a dual Mag system you are correct... Both Mags fire at the same time.  Or SHOULD!  

If because of timing or poor connection they do not there will probably be a poor burn in the cylinder and incomplete burnt fuel will be pushed out the exhause pipes.  

The average EGT is between 1300 to 1400 F.  So jumping from 1400 to 1600 is only a 200 F jump.  That is not much - But it is a temp we do not want to see.  

Cars have experimented with CATALYTIC CONVERTS to burn the incomplete burnt fuel and they get quite hot.  Of course that is also because of the catalytic element.  And burning fuel in the exhaust system with spark plugs and nichrome wire have also been tried.  All this to reduce out exhaust emissions.  

Barry  

On Wed, Apr 28, 2010 at 12:27 PM, Scott DeMeyer <scottsr1100rt(at)yahoo.com (scottsr1100rt(at)yahoo.com)> wrote:          

Hmm, I don't understand how there could be much, if any   unburnt gas in the exhaust pipe while running on one ignition module. It is   my understanding that both plugs fire at the same time on a 912. I would   think you would need a lot of raw fuel to make EGT increase that much. How   could there be enough unburnt gas to make a difference? I would suspect   something else like a plugged jet or intake vacuum leak. 

   I know I've had many issues with the carb sockets coming apart. This   substantially increased my EGT.

   Scott

   --- On Wed, 4/28/10, FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)> wrote:   

   From: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>         

   Subject: Re: Question about High EGTs on a 912

   To: rotaxengines-list(at)matronics.com (rotaxengines-list(at)matronics.com)   

Date: Wednesday, April 28,   2010, 7:23 AM            

--> RotaxEngines-List   message posted by: FLYaDIVE <flyadive(at)gmail.com>

   Les:

   Rich hit the nail on the head.  Unburnt gas burning in the exhaust

   pipes will increase your EGT.

   Prove it to yourself... Fly with ans without a Mag on.

   Barry

   On Wed, Apr 28, 2010 at 12:51 AM, Les Goldner

   <lgold(at)quantum-associates.com> wrote:

   > After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100   RPM

   > yesterday I noticed an EGT problem. Toward the end of the flight, with   OAT

   > about 65F at 2000’, the EGTs started creeping up to 1620F (the   maximum

   > allowed temp) on one exhaust and about 1590F on the other. It dropped   when I

   > reduced RPM to 4000 or raised it to 5500RPM.

   >

   > When I noticed this, I looked around. After getting my head out of a   clouds,

   > I also noticed the engine was running on a single mag. I am hoping that   this

   > was the cause of the overheating, although I don’t understand why   this

   > should be so.

   >

   > It’s going to be raining here (in N. California) for a few   days.  Since I

   > can’t fly to check out if running on both mags will bring the EGTs   down, I

   > was wondering if anyone in Rotax land had an opinion about whether   running

   > on a single mag could causing the high EGTs.  If you don’t   think running on

   > a single mag caused the problem, and you have seen this before, I could   use

   > advice as to how to proceed before tearing the carbs apart.

   >

   > When I can fly again, I’ll report if the mag issue was the culprit   here.

   >

   > Les

   >

   >

   >

   >   

http://www.matronics.com/Navigator?RotaxEngines-List   -->   http://www.matronics.com/contribution

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        [quote][b]

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

b.carl@sympatico.ca

Joined: 20 May 2008
Posts: 77

Posted: Sat May 01, 2010 2:33 pm Post subject: Question about High EGTs on a 912

Les.

 Been there done that,  running on one module  will increase the EGT. You can bet on it.

 Carl

 [quote]   ---

lgold(at)quantum-associat
Guest

Posted: Sun May 02, 2010 1:27 pm Post subject: Question about High EGTs on a 912

Well, the winds calmed down a little and there was no rain yesterday, so I went flying to see if using a single mag had caused the high EGTs last week. You guys were right! Under similar conditions (OAT, RPM, Altitude) where I had experienced 1620F-degree EGTs using one mag, the EGT temps were reading about 100-degrees lower with both mags.  

Glad I don’t have to tear into the carbs. Thanks for the advice guys.

 Les  

       

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of Carl

 Sent: Saturday, May 01, 2010 3:32 PM

 To: rotaxengines-list(at)matronics.com

 Subject: Re: Question about High EGTs on a 912   

  

  

     

Les.  

    

Been there done that,  running on one module will increase the EGT. You can bet on it.  

    

Carl  

   	  Quote: 	
		      

----- Original Message -----   

    

From: Les Goldner (lgold(at)quantum-associates.com)   

    

To: rotaxengines-list(at)matronics.com (rotaxengines-list(at)matronics.com) ; rotax(at)yahoogroups.com (rotax(at)yahoogroups.com)   

    

Sent: Wednesday, April 28, 2010 12:51 AM  

    

Subject: RotaxEngines-List: Question about High EGTs on a 912   

    

   

  

After flying my Zenith 701 w/a Rotax 912ULS a few hundred miles at 5100 RPM yesterday I noticed an EGT problem. Toward the end of the flight, with OAT about 65F at 2000’, the EGTs started creeping up to 1620F (the maximum allowed temp) on one exhaust and about 1590F on the other. It dropped when I reduced RPM to 4000 or raised it to 5500RPM.   

When I noticed this, I looked around. After getting my head out of a clouds, I also noticed the engine was running on a single mag. I am hoping that this was the cause of the overheating, although I don’t understand why this should be so.  

It’s going to be raining here (in N. California) for a few days.  Since I can’t fly to check out if running on both mags will bring the EGTs down, I was wondering if anyone in Rotax land had an opinion about whether running on a single mag could causing the high EGTs.  If you don’t think running on a single mag caused the problem, and you have seen this before, I could use advice as to how to proceed before tearing the carbs apart.  

When I can fly again, I’ll report if the mag issue was the culprit here.   

Les       

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