Today's Message Index:
----------------------
1. 04:53 AM - Re: Bing Type 64 Carb. Idle Mixture Setting (Thom Riddle)
2. 05:47 AM - Re: Re: Bing Type 64 Carb. Idle Mixture Setting (Hugh McKay)
3. 06:12 AM - Re: Bing Type 64 Carb. Idle Mixture Setting (Roger Lee)
4. 06:16 AM - Re: Bing Type 64 Carb. Idle Mixture Setting (Thom Riddle)
5. 06:56 AM - Re: Re: Bing Type 64 Carb. Idle Mixture Setting (Hugh McKay)
6. 08:03 AM - Re: Bing Type 64 Carb. Idle Mixture Setting (Roger Lee)
7. 08:39 AM - Re: Re: Bing Type 64 Carb. Idle Mixture Setting (Hugh McKay)
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Hugh,
If you are happy with the balance/synch of the two carbs but not happy with the
idle mixture, then any adjustments you make to one idle mixture should be done
to both. Once you get the two idle mixtures to where you are happy, then you
should check the synch again. It should not change much, if any, as long as you
make the idle mixture adjustments equal on both carbs.
If I may ask, what triggered the need to make idle mixture adjustments?
--------
Thom Riddle
Buffalo, NY (9G0)
Kolb Slingshot SS-021
Jabiru 2200A #1574
Tennessee Prop 64x32
Don't accept your dog's admiration as conclusive evidence that you are wonderful.
Ann Landers
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332606#332606
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Thom,
Some time ago I had a rough engine problem which was finally traced to a
broken wire at one of the modules. In the course of trying a number of
things to find the problem, one of the things I did was to re-set the idle
mixture. I closed the idle mixture screw on both carbs and then backed them
out the 1.5 turns per Rotax. Unfortunately I did not index the original
position of the screws so I don't know exactly where they were set by the
factory (i.e. 1.5, 1.8 ,or say 2.0 etc). Anyway, my plugs have a black
velvet coating on them every time I change them, and the inside of my
exhaust is black and sooty. My reading has reading on this has indicated
that my idle mix setting is too rich, so I am going to try and readjust them
per the Pro Carb Shop procedure. Any suggestions?
Hugh G. McKay III, P.E.
Senior Consultant
Worldwide Engineering Inc.
4090 North NC Hwy. 16
Denver, NC 28037
Ph. 704-661-8271
Fax 704-483-5466
email hgmckay@bellsouth.net
http://www.wwegeo.com
-----Original Message-----
From: Thom Riddle
Sent: Thursday, March 03, 2011 7:50 AM
Subject: RotaxEngines-List: Re: Bing Type 64 Carb. Idle Mixture Setting
Hugh,
If you are happy with the balance/synch of the two carbs but not happy with
the idle mixture, then any adjustments you make to one idle mixture should
be done to both. Once you get the two idle mixtures to where you are happy,
then you should check the synch again. It should not change much, if any, as
long as you make the idle mixture adjustments equal on both carbs.
If I may ask, what triggered the need to make idle mixture adjustments?
--------
Thom Riddle
Buffalo, NY (9G0)
Kolb Slingshot SS-021
Jabiru 2200A #1574
Tennessee Prop 64x32
Don't accept your dog's admiration as conclusive evidence that you are
wonderful.
Ann Landers
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332606#332606
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Hi Hugh,
The factory setting is 1.5 turns. You can tweak these some and clean up the idle
mixture. It will not effect any thing above idle. The black dry velvet can be
normal and only happens at idle. When you are cruising then this does not happen.
Because of the way the air intakes are setup you can have a slight difference
between sides on the mixture. You actually can just tweak one side if need
be and it won't hurt any thing. The black velvet won't hurt a thing and you
shouldn't be at idle for long periods anyway. Most of the time your engine is
well above that so it isn't a factor so the other option is to just leave it
alone. My plane will have it sometimes and other times it doesn't, plus it may
move from one plug to another. It is a small item and not one that I would worry
too much about.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332616#332616
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Hugh,
Just make small adjustments, no more than 1/8th turn (45 degrees) at a time, on
both carbs, from the original 1.5 turn starting point. Run the engine and check
again.
Keep in mind that these affect only the mixture at idle speed or slightly above
idle speed and that at idle, they must be fairly rich to come off idle smoothly
without stuttering or balking. The plugs will show black sooty appearance after
extended idle periods even when it is adjusted perfectly, because it must
be somewhat rich at idle. The color inside the exhaust tip reflects more accurately
the normal cruise speed mixture, and should be less black and more gray
in color. If you run the engine under less load than recommended (too little
prop pitch or too slow rpm) then the exhaust color may be black. If you have EGTs
installed, the normal cruise temps should be approximately 1,470F with a max
of 1,560F.
In my experience with prop pitched properly, the 912UL will have the proper EGT
readings above 4800 rpm or so with gradual drop off below that speed range.
--------
Thom Riddle
Buffalo, NY (9G0)
Kolb Slingshot SS-021
Jabiru 2200A #1574
Tennessee Prop 64x32
Don't accept your dog's admiration as conclusive evidence that you are wonderful.
Ann Landers
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332617#332617
Message 5
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Thom/Roger,
Thank you for your counsel and advice. My exhaust is certainly not grey. It
is black and sooty! My prop pitch is is 15 degrees which gives me 5100
Static rpm. The following three tests were run to set my prop pitch:
First Test Pitch 17.5 degrees rpm 4600
Second Test Pitch 16.5 degrees rpm 4900
Third Test Pitch 15 degrees rpm 5100
I have been happy with the pitch at 15 degrees. When I cruise I keep the
engine rpm between 5200 to 5400 rpm. Under this condition (cruise) I am not
at WOT. On take off (WOT), my rpm is around 5100. I still think I am too
rich because of the black sooty exhaust.
Hugh G. McKay III, P.E.
Senior Consultant
Worldwide Engineering Inc.
4090 North NC Hwy. 16
Denver, NC 28037
Ph. 704-661-8271
Fax 704-483-5466
email hgmckay@bellsouth.net
http://www.wwegeo.com
-----Original Message-----
From: Thom Riddle
Sent: Thursday, March 03, 2011 9:13 AM
Subject: RotaxEngines-List: Re: Bing Type 64 Carb. Idle Mixture Setting
Hugh,
Just make small adjustments, no more than 1/8th turn (45 degrees) at a time,
on both carbs, from the original 1.5 turn starting point. Run the engine and
check again.
Keep in mind that these affect only the mixture at idle speed or slightly
above idle speed and that at idle, they must be fairly rich to come off idle
smoothly without stuttering or balking. The plugs will show black sooty
appearance after extended idle periods even when it is adjusted perfectly,
because it must be somewhat rich at idle. The color inside the exhaust tip
reflects more accurately the normal cruise speed mixture, and should be less
black and more gray in color. If you run the engine under less load than
recommended (too little prop pitch or too slow rpm) then the exhaust color
may be black. If you have EGTs installed, the normal cruise temps should be
approximately 1,470F with a max of 1,560F.
In my experience with prop pitched properly, the 912UL will have the proper
EGT readings above 4800 rpm or so with gradual drop off below that speed
range.
--------
Thom Riddle
Buffalo, NY (9G0)
Kolb Slingshot SS-021
Jabiru 2200A #1574
Tennessee Prop 64x32
Don't accept your dog's admiration as conclusive evidence that you are
wonderful.
Ann Landers
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332617#332617
Message 6
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Hi Hugh,
With the rpm numbers you give sounds like you are little under propped. What do
you get at WOT flat and level? It sounds like you may be close to 5700 WOT? It
won't hurt anything, but you'll loose a little cruise speed and fuel economy.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332635#332635
Message 7
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| Subject: | Re: Bing Type 64 Carb. Idle Mixture Setting |
Roger,
I never fly WOT while cruising. I will fly today and open her wide open and
check the rpm. I will let you know.
Hugh G. McKay III, P.E.
Senior Consultant
Worldwide Engineering Inc.
4090 North NC Hwy. 16
Denver, NC 28037
Ph. 704-661-8271
Fax 704-483-5466
email hgmckay@bellsouth.net
http://www.wwegeo.com
-----Original Message-----
From: Roger Lee
Sent: Thursday, March 03, 2011 11:00 AM
Subject: RotaxEngines-List: Re: Bing Type 64 Carb. Idle Mixture Setting
Hi Hugh,
With the rpm numbers you give sounds like you are little under propped. What
do you get at WOT flat and level? It sounds like you may be close to 5700
WOT? It won't hurt anything, but you'll loose a little cruise speed and fuel
economy.
--------
Roger Lee
Tucson, Az.
Light Sport Repairman - Maintenance Rated
Rotax Repair Center
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=332635#332635
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