Today's Message Index:
----------------------
0. 12:33 AM - November is Matronics Email List Fund Raiser Month! (Matt Dralle)
1. 02:09 PM - Carb jet changes (Lynn Matteson)
2. 06:02 PM - Re: Carb jet changes (Peter Harris)
3. 06:49 PM - Re: Carb jet changes (Lynn Matteson)
4. 08:49 PM - Re: Carb jet changes (Peter Harris)
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| Subject: | November is Matronics Email List Fund Raiser Month! |
Dear Listers,
You've probably noticed that there are no banner ads or pop-up windows or spam
from any of the List and Forum services at Matronics. These include, for example:
The Email List Postings - http://www.matronics.com/listbrowse
The Email List Forum Site - http://forums.matronics.com
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The List Search Engine - http://www.matronics.com/search
This is because I have always enjoyed a List experience that was completely about
the sport we enjoy - airplanes - and not about advertising!
But running a high performance, highly available service like this isn't free and
a fair amount of money in terms of computer upgrades, business-class Internet
connectivity, and electricity. Consequently, many similar sites turn to advertising
to support these costs. Advertising that you have to look at each and
every time you read an email message or browse the their web site.
Rather than subject my List community to another constant commercial bombardment,
I have chosen to hold a PBS-like fund raiser each year in November to support
the continued operation and upgrade of the List services. It's solely through
the Contributions of List members that the Lists and Forums continue to be
possible!
During the month, I will be sending out a Fund Raiser reminder message every few
days and I ask for your patience and understanding during the month throughout
these regular messages. Think of them as PBS' Pledge Breaks... :-)
To minimize the impact of the Fund Raiser on the List community, I implemented
a new feature late last year specifically related to making Contributions. If
you are an Email List subscriber, once you make a Contribution using the online
web site, you will no longer receive the email from me regarding the Fund Raiser!
There are a couple of exceptions to this, however. If someone replies
to a Contribution message I've sent, you might receive that. Additionally, the
messages will always be posted to the Forums site. To a first order, however,
once you make a Contribution, you won't get my email messages about the Fund
Raiser for the rest of the month. For Contributions by check, the squelch
will take effect once the check is received.
There is a whole new line up of really great Contribution gifts this year! When
you make a qualifying Contribution, you can select one of the many free gifts
that are available during the Fund Raiser. These gifts are provided through
the generous support of a number of our industry's leading supporters including:
Bob Nuckolls - AeroElectric - http://www.aeroelectric.com
Andy Gold - Builder's Bookstore - http://www.buildersbooks.com
Jon Croke - HomebuiltHELP - http://www.homebuilthelp.com
Please visit these guy's respective sites, as they have some great products to
offer and are generously supporting the Matronics List Fund Raiser.
You can make your List Contribution using any one of three secure methods this
year including using a credit card, PayPal, or by personal check. From the Contribution
site, you can select any one of this year's free gifts with a qualifying
Contribution amount. The Contribution page is pretty loooonnnnng this year
in order to list great selection of great gifts available so be sure to scroll
all the way to the bottom of the web page to see everything that's available!
Please make a List Support Contribution:
http://www.matronics.com/contribution
I would like to thank everyone in advance for their generous support! Your Contributions
truely keep this operation afloat!
Thank you,
Matt Dralle
Matronics Email List Forum Administrator
Message 1
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| Subject: | Carb jet changes |
I had an interesting week working on the Bing carb on my serial #2062
Jabiru 2200A engine. I had been running the engine with the cowl off,
and I noticed that fuel was going up the clear tube that is the carb
bowl vent. I assumed that this was a temporary overflow of fuel and
it would soon be gone with the engine running, but it was not.
However, revving the engine got rid of the fuel in that line.
Finally, I closed the main fuel valve, and shut the engine off. I
then took the incoming air hose off the carb, and about a half-cup of
fuel gushed out. This led me to believe that the float needle was
leaking...DUH! It turned out to be exactly that. I ordered a new
needle and seat, and a #40 idle jet. The reason for ordering the jet
was I had read others' comments that the #40 jet took care of their
idling problems. With the new needle and seat in place, and #40 jet
too, the engine ran great, and I could get the idle down to below
900, and it was smooth. Later on, I decide to test the old #45 jet,
so I reinstalled it, and the engine ran great with that (original)
jet. So my major problem was with the float needle and seat, and
nothing else. Amazingly, I have had this bad idle problem for some
time now, and it's been a leaking needle and seat all along. I had
been just learning to deal with the rough idle.
Along with curing the rough idle, I no longer have to shut the main
fuel valve off 30 seconds before I shut the engine down. I thought by
doing this, I was lowering the fuel level in the float bowl, and
thereby keeping the carb from "boiling over", but I was just using up
the excess fuel that was already (probably) laying in the inlet air
hose.
Lynn Matteson
Grass Lake, Michigan
Kitfox IV Speedster w/Jabiru 2200
flying w/420+ hrs
Message 2
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| Subject: | Carb jet changes |
Lynn
I found with the J3300 that the needle seat supplied is 2.25mm and according
to Bing engineers is meant for gravity feed. Anything above 2500RPM and it
ran over rich.
I replaced that seat with the 1.5mm seat recommended by Bing and that cured
rich running all the way to WOT and EGT was within recommended range
although hotter, but if I turned on the electric boost pump even this 1.5mm
seat leaked and caused a big increase in fuel consumption. I discussed with
Jabiru engineers and they confirmed policy to run with the over size seat to
cool the engine and it "works" OK up to 2700 RPM and is "safe" above that
with consumption up to 40LPH.
I am now using TBI and have total control of mixture full range.
Peter H
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Friday, 2 November 2007 7:09 AM
Subject: JabiruEngine-List: Carb jet changes
I had an interesting week working on the Bing carb on my serial #2062
Jabiru 2200A engine. I had been running the engine with the cowl off,
and I noticed that fuel was going up the clear tube that is the carb
bowl vent. I assumed that this was a temporary overflow of fuel and
it would soon be gone with the engine running, but it was not.
However, revving the engine got rid of the fuel in that line.
Finally, I closed the main fuel valve, and shut the engine off. I
then took the incoming air hose off the carb, and about a half-cup of
fuel gushed out. This led me to believe that the float needle was
leaking...DUH! It turned out to be exactly that. I ordered a new
needle and seat, and a #40 idle jet. The reason for ordering the jet
was I had read others' comments that the #40 jet took care of their
idling problems. With the new needle and seat in place, and #40 jet
too, the engine ran great, and I could get the idle down to below
900, and it was smooth. Later on, I decide to test the old #45 jet,
so I reinstalled it, and the engine ran great with that (original)
jet. So my major problem was with the float needle and seat, and
nothing else. Amazingly, I have had this bad idle problem for some
time now, and it's been a leaking needle and seat all along. I had
been just learning to deal with the rough idle.
Along with curing the rough idle, I no longer have to shut the main
fuel valve off 30 seconds before I shut the engine down. I thought by
doing this, I was lowering the fuel level in the float bowl, and
thereby keeping the carb from "boiling over", but I was just using up
the excess fuel that was already (probably) laying in the inlet air
hose.
Lynn Matteson
Grass Lake, Michigan
Kitfox IV Speedster w/Jabiru 2200
flying w/420+ hrs
Message 3
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| Subject: | Re: Carb jet changes |
Hi Peter-
I have an electric boost pump, but only use it to insure fuel at the
carb after any work done, or to check for carb leakage, like I found
this week. A test pilot turned it on while landing a year ago (not
knowing any better) and the engine quit. Without the electric pump,
and with only the mechanical Jabiru pump operating while engine is
running, the gauge reads 2 lbs. pressure, and all seems to be fine.
I should note that when I first got the plane up after the changes,
it was running hotter on the right-hand 2 cylinders. I rotated the
carb according to the "old wives tale", that is rotate the top of the
carb towards the cool, rich side, and that helped. I then rotated it
again, a little more this time, and the cylinders are within 60-70 F
of one another, for most of the operating range...certainly where it
operates the most, at cruising speed. Having had the plenum chamber
and carb off last week I can see how this works. If the carb is
rotated, the spray pattern will change in respect to the divider that
is situated inside the plenum chamber. Apparently if the carb top is
rotated towards the cool side, the spray pattern is divided more
toward the hot, lean side, and the temps between the two sides become
closer together. At least that's what I've been able to observe.
It's late at night and my memory is fading...what's TBI? A type of
carb, I'm assuming? I'm just not recalling....
Lynn Matteson
Grass Lake, Michigan
Kitfox IV Speedster w/Jabiru 2200
flying w/420+ hrs
On Nov 1, 2007, at 9:01 PM, Peter Harris wrote:
> <peterjfharris@bigpond.com>
>
> Lynn
> I found with the J3300 that the needle seat supplied is 2.25mm and
> according
> to Bing engineers is meant for gravity feed. Anything above 2500RPM
> and it
> ran over rich.
> I replaced that seat with the 1.5mm seat recommended by Bing and
> that cured
> rich running all the way to WOT and EGT was within recommended range
> although hotter, but if I turned on the electric boost pump even
> this 1.5mm
> seat leaked and caused a big increase in fuel consumption. I
> discussed with
> Jabiru engineers and they confirmed policy to run with the over
> size seat to
> cool the engine and it "works" OK up to 2700 RPM and is "safe"
> above that
> with consumption up to 40LPH.
> I am now using TBI and have total control of mixture full range.
> Peter H
>
> -----Original Message-----
> From: owner-jabiruengine-list-server@matronics.com
> [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of
> Lynn
> Matteson
> Sent: Friday, 2 November 2007 7:09 AM
> To: jabiruengine-list@matronics.com
> Subject: JabiruEngine-List: Carb jet changes
>
> <lynnmatt@jps.net>
>
> I had an interesting week working on the Bing carb on my serial #2062
> Jabiru 2200A engine. I had been running the engine with the cowl off,
> and I noticed that fuel was going up the clear tube that is the carb
> bowl vent. I assumed that this was a temporary overflow of fuel and
> it would soon be gone with the engine running, but it was not.
> However, revving the engine got rid of the fuel in that line.
> Finally, I closed the main fuel valve, and shut the engine off. I
> then took the incoming air hose off the carb, and about a half-cup of
> fuel gushed out. This led me to believe that the float needle was
> leaking...DUH! It turned out to be exactly that. I ordered a new
> needle and seat, and a #40 idle jet. The reason for ordering the jet
> was I had read others' comments that the #40 jet took care of their
> idling problems. With the new needle and seat in place, and #40 jet
> too, the engine ran great, and I could get the idle down to below
> 900, and it was smooth. Later on, I decide to test the old #45 jet,
> so I reinstalled it, and the engine ran great with that (original)
> jet. So my major problem was with the float needle and seat, and
> nothing else. Amazingly, I have had this bad idle problem for some
> time now, and it's been a leaking needle and seat all along. I had
> been just learning to deal with the rough idle.
>
> Along with curing the rough idle, I no longer have to shut the main
> fuel valve off 30 seconds before I shut the engine down. I thought by
> doing this, I was lowering the fuel level in the float bowl, and
> thereby keeping the carb from "boiling over", but I was just using up
> the excess fuel that was already (probably) laying in the inlet air
> hose.
>
>
> Lynn Matteson
Message 4
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| Subject: | Carb jet changes |
Lynn
By TBI I mean throttle body fuel injection. I have a 45mm throttle body with
two injectors.
Rotating the carb. means that the partly opened butterfly is directing the
air/fuel flow to one side or the other and this affects mixture rich or lean
each side of the plenum.
With the throttle body I have it mounted so the butterfly axis is horizontal
and the problem does not arise.
Peter H
-----Original Message-----
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Lynn
Matteson
Sent: Friday, 2 November 2007 11:49 AM
Subject: Re: JabiruEngine-List: Carb jet changes
Hi Peter-
I have an electric boost pump, but only use it to insure fuel at the
carb after any work done, or to check for carb leakage, like I found
this week. A test pilot turned it on while landing a year ago (not
knowing any better) and the engine quit. Without the electric pump,
and with only the mechanical Jabiru pump operating while engine is
running, the gauge reads 2 lbs. pressure, and all seems to be fine.
I should note that when I first got the plane up after the changes,
it was running hotter on the right-hand 2 cylinders. I rotated the
carb according to the "old wives tale", that is rotate the top of the
carb towards the cool, rich side, and that helped. I then rotated it
again, a little more this time, and the cylinders are within 60-70 F
of one another, for most of the operating range...certainly where it
operates the most, at cruising speed. Having had the plenum chamber
and carb off last week I can see how this works. If the carb is
rotated, the spray pattern will change in respect to the divider that
is situated inside the plenum chamber. Apparently if the carb top is
rotated towards the cool side, the spray pattern is divided more
toward the hot, lean side, and the temps between the two sides become
closer together. At least that's what I've been able to observe.
It's late at night and my memory is fading...what's TBI? A type of
carb, I'm assuming? I'm just not recalling....
Lynn Matteson
Grass Lake, Michigan
Kitfox IV Speedster w/Jabiru 2200
flying w/420+ hrs
On Nov 1, 2007, at 9:01 PM, Peter Harris wrote:
> <peterjfharris@bigpond.com>
>
> Lynn
> I found with the J3300 that the needle seat supplied is 2.25mm and
> according
> to Bing engineers is meant for gravity feed. Anything above 2500RPM
> and it
> ran over rich.
> I replaced that seat with the 1.5mm seat recommended by Bing and
> that cured
> rich running all the way to WOT and EGT was within recommended range
> although hotter, but if I turned on the electric boost pump even
> this 1.5mm
> seat leaked and caused a big increase in fuel consumption. I
> discussed with
> Jabiru engineers and they confirmed policy to run with the over
> size seat to
> cool the engine and it "works" OK up to 2700 RPM and is "safe"
> above that
> with consumption up to 40LPH.
> I am now using TBI and have total control of mixture full range.
> Peter H
>
> -----Original Message-----
> From: owner-jabiruengine-list-server@matronics.com
> [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of
> Lynn
> Matteson
> Sent: Friday, 2 November 2007 7:09 AM
> To: jabiruengine-list@matronics.com
> Subject: JabiruEngine-List: Carb jet changes
>
> <lynnmatt@jps.net>
>
> I had an interesting week working on the Bing carb on my serial #2062
> Jabiru 2200A engine. I had been running the engine with the cowl off,
> and I noticed that fuel was going up the clear tube that is the carb
> bowl vent. I assumed that this was a temporary overflow of fuel and
> it would soon be gone with the engine running, but it was not.
> However, revving the engine got rid of the fuel in that line.
> Finally, I closed the main fuel valve, and shut the engine off. I
> then took the incoming air hose off the carb, and about a half-cup of
> fuel gushed out. This led me to believe that the float needle was
> leaking...DUH! It turned out to be exactly that. I ordered a new
> needle and seat, and a #40 idle jet. The reason for ordering the jet
> was I had read others' comments that the #40 jet took care of their
> idling problems. With the new needle and seat in place, and #40 jet
> too, the engine ran great, and I could get the idle down to below
> 900, and it was smooth. Later on, I decide to test the old #45 jet,
> so I reinstalled it, and the engine ran great with that (original)
> jet. So my major problem was with the float needle and seat, and
> nothing else. Amazingly, I have had this bad idle problem for some
> time now, and it's been a leaking needle and seat all along. I had
> been just learning to deal with the rough idle.
>
> Along with curing the rough idle, I no longer have to shut the main
> fuel valve off 30 seconds before I shut the engine down. I thought by
> doing this, I was lowering the fuel level in the float bowl, and
> thereby keeping the carb from "boiling over", but I was just using up
> the excess fuel that was already (probably) laying in the inlet air
> hose.
>
>
> Lynn Matteson
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