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447 exhaust temperarures

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DAquaNut(at)aol.com
Guest

Posted: Sun Feb 10, 2008 8:19 pm Post subject: 447 exhaust temperarures

Group,

  

   I am still plagued with too high of exhaust temps. I have tried  different jet needles needle jets and main jets but there seems to always be a  hot spot between 4000 and 5200 rpms.    Question      what is the minimum exhaust temp that is  recommended for the Rotax 447 ?    On climb out with the 170  main jet i am seeing 1000*. At other rpms, egts  will get to 1150 or  1175.  Will it hurt anything if I run it with the EGTS at 1000*    I have it propped for 6250 static and the heads are at 350 *or so most of the  time. This 447 is such a royal pain. I am thinking of getting one of those in  flight adjustable carb mixture  controls if I can.

  

          

            Ed   Diebel       FF #   62



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ulflyer(at)verizon.net
Guest

Posted: Sun Feb 10, 2008 9:07 pm Post subject: 447 exhaust temperarures

Ed, 

 Do you have an adjustable pitch prop?  Actually 1000* degrees F is OK - go to much above that and I would start getting concerned.



 High EGT's often indicate you might need to load the engine a little more by increasing your prop's pitch.  We set our new 447's to 5900 static (tail tied down full throttle) and get about 6000-6100 RPM on full throttle on takeoff.  A little more pitch isn't going to hurt anything.  Try it and see what it does.



 What's the EGT numbers doing when you pull back power some such as on final.  For some reason I noticed that FireFly's have a tenancy to peak EGT's when power is reduced some, not completely on final.  

   

 It's been so long since I touched our old Kolb FireFly, I can't recall what jets and needles we ran in it - I know for sure we changed the original main jet.  



 There was a post about a needle to use to reduce high mid-range EGT temp's on 02:03 PM 8/11/04 -0400, by: Gene Ledbetter.  Might want to take a look at it.  I got the needle but hadn't tried it.  

 jerb



 

 At 10:16 PM 2/10/2008, you wrote:

 [quote]Group,

  

   I am still plagued with too high of exhaust temps. I have tried different jet needles needle jets and main jets but there seems to always be a hot spot between 4000 and 5200 rpms.   Question      what is the minimum exhaust temp that is recommended for the Rotax 447 ?    On climb out with the 170 main jet i am seeing 1000*. At other rpms, egts  will get to 1150 or 1175.  Will it hurt anything if I run it with the EGTS at 1000*   I have it propped for 6250 static and the heads are at 350 *or so most of the time. This 447 is such a royal pain. I am thinking of getting one of those in flight adjustable carb mixture  controls if I can.

  

          

            Ed  Diebel       FF #  62

 



 

  Who's never won?  Biggest Grammy Award surprises of all time on AOL Music.



 [b]

Steve Boetto

Joined: 11 Jan 2006
Posts: 365

Posted: Mon Feb 11, 2008 9:51 am Post subject: 447 exhaust temperarures

Ed,  I still follow John H's advice on 2 stroke.   Put the  needles and settings back to the factory setup. Then adjust your prop for 6500  in full throttle level flight. Your temps should be fine.  As far as flying  pulled back to 5200,  IMHO,  I run my 447 at 5800 to 6000 rpm.   As you pull back the power you will be leaning the engine and it will run  hotter. I do all of my descents at idle.

  

 Steve

  

  In a message dated 2/10/2008 11:20:12 P.M. Eastern Standard Time,  DAquaNut(at)aol.com writes:

  	  Quote: 	
		     Group,

    

     I am still plagued with too high of exhaust temps. I have tried    different jet needles needle jets and main jets but there seems to always be a    hot spot between 4000 and 5200 rpms.      Question      what is the minimum exhaust temp that    is recommended for the Rotax 447 ?    On climb out with    the 170 main jet i am seeing 1000*. At other rpms, egts  will get to    1150 or 1175.  Will it hurt anything if I run it with the EGTS at    1000*   I have it propped for 6250 static and the heads are at 350    *or so most of the time. This 447 is such a royal pain. I am thinking of    getting one of those in flight adjustable carb mixture  controls if I    can.

    

            

              Ed     Diebel       FF #     62



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tkrolfe(at)toast.net
Guest

Posted: Mon Feb 11, 2008 9:55 am Post subject: 447 exhaust temperarures

DAquaNut(at)aol.com (DAquaNut(at)aol.com) wrote:  	  Quote: 	
		              Group,

    

     I am still plagued with too high of exhaust temps. I have tried different jet needles needle jets and main jets but there seems to always be a hot spot between 4000 and 5200 rpms.   Question      what is the minimum exhaust temp that is recommended for the Rotax 447 ?    On climb out with the 170 main jet i am seeing 1000*. At other rpms, egts  will get to 1150 or 1175.  Will it hurt anything if I run it with the EGTS at 1000*   I have it propped for 6250 static and the heads are at 350 *or so most of the time. This 447 is such a royal pain. I am thinking of getting one of those in flight adjustable carb mixture  controls if I can.

    

            

              Ed  Diebel       FF #  62

   	
 

 Ed,

 

 What exhaust temps are you looking for?  I don't consider the numbers your giving as being too high.  Your head temps are up there, but still tolerable.  Why the 170 main jet which makes it leaner?  165 is stock.  What position is you needle clip in?

 

 I run my 447 with the stock jet, 11G2 needle in the third notch from the top,  Head temps from 275 to 325 and exhaust temps from 1075 to 1175 depending on throttle some times peaking at 1200.  Now have 795 hr.s on it and running strong!

 

 Check your Rotax service information manual and I think you will find that your exhaust temps are actually low.  I'm sure you are aware that most of the gauges we use are not certified and can vary considerably from one another.

 

 Sounds like your prop pitch is OK by the static number you posted.  I"m closer to 6400 since altering my tips on my wood Tennessee prop.

 

 Sounds like your running a little rich.  Just my thought on the matter for what they are worth!!!

 

 Terry -  FireFly #95

    [quote][b]

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Tue Feb 12, 2008 10:39 am Post subject: Re: 447 exhaust temperarures

 	  Steve Boetto wrote: 	
		  Ed,  I still follow John H's advice on 2 stroke.   Put the  needles and settings back to the factory setup. Then adjust your prop for 6500  in full throttle level flight. Your temps should be fine.  As far as flying  pulled back to 5200,  IMHO,  I run my 447 at 5800 to 6000 rpm.ï¿½  As you pull back the power you will be leaning the engine and it will run  hotter. I do all of my descents at idle.

  

 Steve

  

	




You should not have to change your jets.  Set up the carb as per manufacturers specs, everything where the manual says, and then pitch your prop to get the temps you want.  After trying a lot of different things, this worked on the 447 that I fly.  More pitch = lower temps and was the most effective at controlling temps and resulted in the smoothest running engine.   BTW 1000 EGT on climbout is fine, it can even be a down in the 900's in climb without a problem., dont expect to be seeing the same temps on cruise and climbout, they will change a lot.   



1175 is to high in cruise, put some more pitch in your prop, just increasing the prop pitch for 100 RPM less static RPM will bring that cruise temp right down to where you want it.  My static RPM is very close to 6000 RPM.



Mike

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DAquaNut(at)aol.com
Guest

Posted: Tue Feb 12, 2008 8:01 pm Post subject: 447 exhaust temperarures

In a message dated 2/12/2008 12:42:26 P.M. Central Standard Time,  orcabonita(at)hotmail.com writes:

  	  Quote: 	
		       More pitch = lower temps and was the most effective at controlling temps and    resulted in the smoothest running engine.   BTW 1000 EGT on climbout    is fine, it can even be a down in the 900's in climb without a problem., dont    expect to be seeing the same temps on cruise and climbout, they will change a    lot.   



1175 is to high in cruise, put some more pitch in    your prop, just increasing the prop pitch for 100 RPM less static RPM will    bring that cruise temp right down to where you want it.  My static RPM is    very close to 6000 RPM.



Mike



	


 

                 More pitch= lower EGTS   More pitch= higher CHTS     When I add pitch it causes my Chts to go up around 400*    I need  a balance between EGTS and CHTS.    DO I go up on my main jets  until my hot spots dont go over 1175 *     It gets the  hottest around 4000 rpm and 5000 rpm.  I just dont want to creat a  situation that causes excess carbon.  There is another guy here running 180  main jets in his 447 in a J-3  Kitten. I think  I Think I am  going to raise my main jet size until it does not get above 1175* at  anytime.  My plugs are very light in color and I have had the engine run a  little rough and when I pull the enrichener        the roughness smoothed out .

  

  

                       Ed     FF # 62 



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jindoguy(at)gmail.com
Guest

Posted: Wed Feb 13, 2008 10:36 am Post subject: 447 exhaust temperarures

Ed, I'll go on record with the others who have recommended that before you do anything else you set the jets and needles back to stock. Record and report back what your results are. 

By going back to stock I mean setting the idle screw jet at .5 turns out, a 165 main jet, 2.70 needle jet and a 15K2 jet needle with the clip set at the #2 position from the top as specified in the Bing manual and the Rotax Illustrated Parts Catalog (page 9.3.1-7). 

 Check the carburetor boot for cracks and that the clamps are properly tightened.

Check the spark plugs that they are the right type (B8ES) and correct gap (.018") and the caps are 5K ohm resistance and fit on the plug with a snap.

 Check the fan belt tension. If you have run the engine more than 10 hours it probably needs adjustment.

On the 447 I set up on a trike last October I set the prop to give 6200 RPM static which resulted in 6500 WOT in level flight. 

 After breakin the engine would approach 450 degrees on full throttle climb out and settled down to 380 during cruise at 5500 RPM. 

Per Rotax Operation Manual, page 10-1 CHT's measured at the spark plug seat have a max of 500 degrees F and a normal operating range of 374 to 446 degrees F. Differences between cylinders are 36 degrees F max. 

 As for EGT's, Rotax gives no recommendations for the 447, although the 503 max EGT is 1200 degrees.

These condiditons will give you a baseline from which to start. If you just start changing things you are probably headed for grief.

 Just my opinion, yours may vary.



Rick

 

On Feb 12, 2008 9:59 PM,  <DAquaNut(at)aol.com (DAquaNut(at)aol.com)> wrote:

[quote]        In a message dated 2/12/2008 12:42:26 P.M. Central Standard Time,  orcabonita(at)hotmail.com (orcabonita(at)hotmail.com) writes:

  	  Quote: 	
		       More pitch = lower temps and was the most effective at controlling temps and    resulted in the smoothest running engine.   BTW 1000 EGT on climbout    is fine, it can even be a down in the 900's in climb without a problem., dont    expect to be seeing the same temps on cruise and climbout, they will change a    lot.   



1175 is to high in cruise, put some more pitch in    your prop, just increasing the prop pitch for 100 RPM less static RPM will    bring that cruise temp right down to where you want it.  My static RPM is    very close to 6000 RPM.



Mike



	


 

                 More pitch= lower EGTS   More pitch= higher CHTS     When I add pitch it causes my Chts to go up around 400*    I need  a balance between EGTS and CHTS.    DO I go up on my main jets  until my hot spots dont go over 1175 *     It gets the  hottest around 4000 rpm and 5000 rpm.  I just dont want to creat a  situation that causes excess carbon.  There is another guy here running 180  main jets in his 447 in a J-3  Kitten. I think  I Think I am  going to raise my main jet size until it does not get above 1175* at  anytime.  My plugs are very light in color and I have had the engine run a  little rough and when I pull the enrichener        the roughness smoothed out .

  

  

                       Ed     FF # 62 



  The year's hottest artists on the red carpet at the Grammy Awards.  AOL Music takes you there.

     	  Quote: 	
		  

	


[b]

DAquaNut(at)aol.com
Guest

Posted: Wed Feb 13, 2008 7:44 pm Post subject: 447 exhaust temperarures

In a message dated 2/13/2008 12:37:29 P.M. Central Standard Time,  jindoguy(at)gmail.com writes:

  	  Quote: 	
		  On the    447 I set up on a trike last October I set the prop to give 6200 RPM static    which resulted in 6500 WOT in level flight. 

After breakin the engine would    approach 450 degrees on full throttle climb out and settled down to 380 during    cruise at 5500 RPM. 

Per Rotax Operation Manual, page 10-1 CHT's measured    at the spark plug seat have a max of 500 degrees F and a normal operating    range of 374 to 446 degrees F. Differences between cylinders are 36 degrees F    max. 

As for EGT's, Rotax gives no recommendations for the 447, although    the 503 max EGT is 1200 degrees.

These condiditons will give you a baseline    from which to start. If you just start changing things you are probably headed    for grief.

Just my opinion, yours may  vary.



Rick



	


 

                  My 447 has never seen CHTS  higher than 400*.  If you are suggesting  its ok to run with the heads at 400* I can put in more pitch which will cool the  CHTS quite a bit I am certain ,but I am fearful of running with 400* CHTS  as I Know of a guy that had a 503 seize at 400* CHTS.  I seem to have  higher EGTS now that I am forced to run 10% alcohol, as that is all that is  available in Houston.

  

  

                 Ed 



The year's hottest artists on the red carpet at the Grammy Awards.  AOL Music takes you there.

  [quote][b]

jindoguy(at)gmail.com
Guest

Posted: Wed Feb 13, 2008 9:20 pm Post subject: 447 exhaust temperarures

Ed, someone correct me if I'm wrong, but more pitch should send the CHT readings up, not down. More pitch would bring the EGT's down.

If you still have a calibrated iron from covering you can check the CHT sender to see if it's working properly. Or borrow a laser thermometer and check the readings you're getting with that.

 

Rick



On Feb 13, 2008 9:40 PM,  <DAquaNut(at)aol.com (DAquaNut(at)aol.com)> wrote:

[quote]       In a message dated 2/13/2008 12:37:29 P.M. Central Standard Time,  jindoguy(at)gmail.com (jindoguy(at)gmail.com) writes:

  	  Quote: 	
		  On the    447 I set up on a trike last October I set the prop to give 6200 RPM static    which resulted in 6500 WOT in level flight. 

After breakin the engine would    approach 450 degrees on full throttle climb out and settled down to 380 during    cruise at 5500 RPM. 

Per Rotax Operation Manual, page 10-1 CHT's measured    at the spark plug seat have a max of 500 degrees F and a normal operating    range of 374 to 446 degrees F. Differences between cylinders are 36 degrees F    max. 

As for EGT's, Rotax gives no recommendations for the 447, although    the 503 max EGT is 1200 degrees.

These condiditons will give you a baseline    from which to start. If you just start changing things you are probably headed    for grief.

Just my opinion, yours may  vary.



Rick



	


 



                  My 447 has never seen CHTS  higher than 400*.  If you are suggesting  its ok to run with the heads at 400* I can put in more pitch which will cool the  CHTS quite a bit I am certain ,but I am fearful of running with 400* CHTS  as I Know of a guy that had a 503 seize at 400* CHTS.  I seem to have  higher EGTS now that I am forced to run 10% alcohol, as that is all that is  available in Houston.

  

  

                 Ed 



 The year's hottest artists on the red carpet at the Grammy Awards.  AOL Music takes you there.

    	  Quote: 	
		  

	




[b]

DAquaNut(at)aol.com
Guest

Posted: Wed Feb 13, 2008 9:46 pm Post subject: 447 exhaust temperarures

In a message dated 2/13/2008 11:20:52 P.M. Central Standard Time,  jindoguy(at)gmail.com writes:

  	  Quote: 	
		  Ed,    someone correct me if I'm wrong, but more pitch should send the CHT readings    up, not down. More pitch would bring the EGT's down.

If you still have a    calibrated iron from covering you can check the CHT sender to see if it's    working properly. Or borrow a laser thermometer and check the readings you're    getting with that.



Rick

	


 

          My mistake Rick! I  intended to say more pitch will cool my EGTS. My head temps go up with more  pitch. With the Ivo pitched for 6250 RPM I am seeing 350-375* CHTS If I increase  the pitch to bring down egts my heads go up around 400* or so.   I  guess I will crank in a little more pitch and see what  happens.  

  

  

                Ed



The year's hottest artists on the red carpet at the Grammy Awards.  AOL Music takes you there.

  [quote][b]

jindoguy(at)gmail.com
Guest

Posted: Thu Feb 14, 2008 7:45 am Post subject: 447 exhaust temperarures

Ed, have you checked the belt tension? If it's slipping, that could account for a lot. Also, how is the airpath to the fan inlet?



Rick



On Wed, Feb 13, 2008 at 11:44 PM,  <DAquaNut(at)aol.com (DAquaNut(at)aol.com)> wrote:

 [quote]      In a message dated 2/13/2008 11:20:52 P.M. Central Standard Time,  jindoguy(at)gmail.com (jindoguy(at)gmail.com) writes:

  	  Quote: 	
		  Ed,    someone correct me if I'm wrong, but more pitch should send the CHT readings    up, not down. More pitch would bring the EGT's down.

If you still have a    calibrated iron from covering you can check the CHT sender to see if it's    working properly. Or borrow a laser thermometer and check the readings you're    getting with that.



Rick

	


 

 

         My mistake Rick! I  intended to say more pitch will cool my EGTS. My head temps go up with more  pitch. With the Ivo pitched for 6250 RPM I am seeing 350-375* CHTS If I increase  the pitch to bring down egts my heads go up around 400* or so.   I  guess I will crank in a little more pitch and see what  happens.  

  

  

                Ed



 The year's hottest artists on the red carpet at the Grammy Awards.  AOL Music takes you there.

    	  Quote: 	
		  

	




[b]

DAquaNut(at)aol.com
Guest

Posted: Thu Feb 14, 2008 7:06 pm Post subject: 447 exhaust temperarures

In a message dated 2/14/2008 9:47:22 A.M. Central Standard Time,  jindoguy(at)gmail.com writes:

  	  Quote: 	
		  Ed, have    you checked the belt tension? If it's slipping, that could account for a lot.    Also, how is the airpath to the fan  inlet?



Rick

	


 

            The belt is  tight and airflow unobstructed!  Thanks!

  

  

  

                          Ed     FF#62           Do Not Archive



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