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  #11  
Old 04-29-2013, 08:29 PM
Geico266's Avatar
Geico266 Geico266 is offline
 
Join Date: Feb 2005
Location: Huskerland, USA
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Quote:
Originally Posted by sdixon View Post
Switched over the pair of egt leads. Problem traveled to right side. Now I'm checking for induction leaks and replacing probe
I'm not the sharpest tool in the shed, but if the high temp traveled with the leads being switched it is not a problem with the engine, it is a problem with the probe.
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  #12  
Old 04-29-2013, 09:26 PM
RFSchaller RFSchaller is offline
 
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Geico,

I hate it when logic kicks my butt! :-)

Rich
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  #13  
Old 04-30-2013, 12:34 AM
crashley crashley is offline
 
Join Date: Jun 2009
Location: hazelwood north vic
Posts: 176
Default egt

Dont touch the mixture screws the problem is with your sensor or probes
if the problem can be swapped from one side to the other by swapping the probes the problem is with the wiring not the engine
check the wire colors all the way to the monitor you will find there is a swap somewhere
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  #14  
Old 04-30-2013, 04:28 AM
N223JH N223JH is offline
 
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Location: Boerne, TX
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If the problem moved to the other line on the Dynon EGT display, it is the probe or (somehow) its installation. Call Dynon or take your chances getting an answer on the Dynon Forum. In my experience the techs have been very helpful.

If the fix is a new probe you can consider yourself lucky as many of us have dealt with more time-consuming and costly glitches with the Rotax-Dynon interface.

Jim
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  #15  
Old 04-30-2013, 07:35 AM
Mich48041 Mich48041 is online now
 
Join Date: Apr 2008
Location: Riley TWP MI
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sdixon determined that one of the EGT probes is sending out a signal that is about 90 degrees hotter than the other probe. Is the probe lying or telling the truth? The only way to find out is to replace the probe or swap it with the one on the other side.
But why bother? I would raise the EGT alarm setpoint or disable it after reading the article below by Mike Busch who is an expert on aircraft engines. His articles have appeared in Sport Aviation.

Joe Gores

https://www.savvyanalysis.com/articl...myths-debunked
Mike Busch said,
Quote:
Even if indicated EGT accurately reported actual exhaust gas temperature (which it doesn't), it's important to understand that exhaust gas temperature does not correlate with stress on the engine . . . . .Absolute values of EGT (e.g., 1475°F) are simply not meaningful and are best ignored. There is no such thing as a maximum EGT limit or red-line, and trying to keep absolute EGTs below some particular value - or even worse, leaning to a particular absolute EGT value - is simply wrongheaded. Don't do it. If you must fixate on those digital engine monitor readouts, fixate on something important like CHT.

Last edited by Mich48041 : 04-30-2013 at 07:46 AM. Reason: Corrected spelling error
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  #16  
Old 04-30-2013, 02:48 PM
sdixon sdixon is offline
 
Join Date: Jan 2012
Location: Milton, Vermont
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The chat is just fine. Swithcing probes this week........btw. If you pull the choke out 1/8 inch it cools down everything whichnisnwhy I don't underrstand why it is not proper to balance the richness based off of egt values. The mechanical balance. The pneumatic balance and then the richness balance.........any takers on that?
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  #17  
Old 04-30-2013, 09:48 PM
crashley crashley is offline
 
Join Date: Jun 2009
Location: hazelwood north vic
Posts: 176
Default confused

Quote:
Originally Posted by RFSchaller View Post
I don't claim to be an expert, but when I went to the CPS Rotax course they said this (the adjustment on the bottom of the carb) is a factory setting that shouldn't be messed with.
Hi when you said you switched over the leads did you swap them from the left side of the engine to the right side or did you reverse the polarity of the leads on one side if you switched the leads from the left sensor to the right sensor and the high temp moved to the other side the problem must be with the wiring

and when you pulled the choke out did both temps drop or only one side
and the reason for not adjusting the mixture is that the rotax manual specificaly states that they factory set and must not be adjusted

running with the choke out will make it run coooler but also very rich and will use heaps of fuel
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  #18  
Old 05-01-2013, 06:12 AM
Limey Limey is offline
 
Join Date: Dec 2012
Location: Pentwater, MI
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Quote:
Originally Posted by crashley View Post
running with the choke out will make it run coooler but also very rich and will use heaps of fuel
This is correct - it can also lead to unburned fuel in the cylinders which washes off the lubricant and can lead to rapid bore wear. A good reason to get the engine off the choke as quickly as possible.
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  #19  
Old 05-01-2013, 08:01 AM
Mich48041 Mich48041 is online now
 
Join Date: Apr 2008
Location: Riley TWP MI
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Quote:
if you switched the leads from the left sensor to the right sensor and the high temp moved to the other side the problem must be with the wiring
It all depends on where the wires are switched, EFIS end, middle, or probe end. There is a convenient splice in the middle at the firewall. If the wires are switched close to the probes, then the wire from that point to the EFIS has not changed. Wire that was connected to the left side of the EFIS is still connected to the left side of the EFIS.
Joe Gores
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  #20  
Old 05-01-2013, 05:30 PM
edward7048 edward7048 is offline
 
Join Date: May 2010
Location: Kokomo, In.
Posts: 109
Default high egt on left side

I have the same problem as the first person has, I switch the probes
and the problem stayed with the left side. The left side is always
higher than the right side. When at full throtle both are the same.
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