Today's Message Index:
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1. 04:11 AM - Re: Float Level (Lynn Matteson)
2. 05:39 AM - Re: Float Level (Dave G.)
3. 03:25 PM - Re: Float Level (Lynn Matteson)
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Ron-
Did you happen to measure (with a # drill) the 240 main before you
installed it? Or for that matter the 220? I measured my 220 and it
is .078". I'm thinking of drilling my 220 out, as it seems to be the
reason that my EGT's are still up in the 1400's when I've gone to a
larger needle jet (twice) and it didn't lower the EGT's.
Lynn
On Apr 28, 2008, at 5:19 PM, RONAL SMITH wrote:
> My understanding is that any EGT temp. 1400 F or below is fine with
> the Jabiru 2200 engine. I was getting temps up to 1500, so I
> changed the needle jet from 276 to 280 and the main jet from 220 to
> 240. Now my high temp in cruise is 1375 with the OAT 65 F or
> above. My engine is Ser. No. 2030.
> Ron Smith
> Kitfox 4 with Jabiru 2200
> forums.matronics.com_-
> ============================================================ _-
> contribution_-
> ===========================================================
Message 2
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Hi Lynn. I'm not trying to come across "all expert" but we tried simply
drilling a larger hole in mains years ago with Mikuni carbs on motorcycles
and the results were unpredictable. It might be better to simply buy a
larger main jet from Bing if you feel the need. I've heard you can do it
with flow testing but I figured it wasn't worth the effort.
----- Original Message -----
From: "Lynn Matteson" <lynnmatt@jps.net>
Sent: Sunday, May 04, 2008 8:06 AM
Subject: Re: JabiruEngine-List: Float Level
>
> Ron-
> Did you happen to measure (with a # drill) the 240 main before you
> installed it? Or for that matter the 220? I measured my 220 and it is
> .078". I'm thinking of drilling my 220 out, as it seems to be the reason
> that my EGT's are still up in the 1400's when I've gone to a larger
> needle jet (twice) and it didn't lower the EGT's.
>
> Lynn
>
> On Apr 28, 2008, at 5:19 PM, RONAL SMITH wrote:
>
>> My understanding is that any EGT temp. 1400 F or below is fine with the
>> Jabiru 2200 engine. I was getting temps up to 1500, so I changed the
>> needle jet from 276 to 280 and the main jet from 220 to 240. Now my
>> high temp in cruise is 1375 with the OAT 65 F or above. My engine is
>> Ser. No. 2030.
>> Ron Smith
>> Kitfox 4 with Jabiru 2200
>> forums.matronics.com_-
>> ============================================================ _-
>> contribution_-
>> ===========================================================
>
>
>
Message 3
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Thanks for the input, Dave.
I too, was a little wary when I heard folks talk about drilling jets
out, thinking it would be better to buy them and know that the
precision would be better. I've got a metal lathe, and had good
success in drilling my 2.76 needle jet out to a #33 drill size...
0.113". This didn't change my EGT's any (leading me to think the main
needed to be larger) but today I did something else. I was having
trouble getting one of my EGT's below the 1400 F range, and the left
bank was always the hottest. Well today I decided to rotate the carb
as per the suggested manner....top towards the cool side. I had done
this before, but when I recently added air-straightening vanes inside
my air duct (attaches directly to carb) I made sure the carb was
rotated directly vertical. I had flown it for a week or so that way,
and today I decided to try rotating it again. I am quite pleased to
say that this time it worked, and I now have 3 cylinders within about
30 degrees of one another, and one (#3) that is about 70 degrees
colder. I'm ready to live with that, I think. I no longer see the 1400
+ reading on cyl #4, like I had before. Knowing me, I'll probably try
to tweak the rotation a bit and see if #3 and #4 can be brought a bit
closer together.
It was interesting to note that during previous operation at around
2850 rpm, straight and level, my EIS would alarm showing high EGT
spread of over 212 F. I had arbitrarily set this number into the EIS
unit some time ago. Now I don't get that alarm, or see such a large
spread. I wish I could figure a way to precisely control the position
of the carb when rotating it, or doing the rotation from the cabin,
but that's asking for too much. : )
So for the time being, I won't be drilling my main out, or do any
other jet tweaking. I'll just concentrate on trying to fine-tune the
position of the carb.
Maybe what is needed is a cockpit-controlled splitter that will allow
for diverting the mixture toward the hottest cylinder/bank. It
wouldn't need to be much...just a lever-controlled vane positioned in
front of the built-in splitter. This is getting a bit radical, and
I'm hoping that persons with better testing facilities than I (read:
the Jabiru engineers) could do some work on the carb and come up with
a closer cylinder-to-cylinder match of EGT's.
Lynn Matteson
Grass Lake, Michigan
Kitfox IV Speedster w/Jabiru 2200
flying w/503+ hrs
On May 4, 2008, at 8:20 AM, Dave G. wrote:
> <d.goddard@ns.sympatico.ca>
>
> Hi Lynn. I'm not trying to come across "all expert" but we tried
> simply drilling a larger hole in mains years ago with Mikuni carbs
> on motorcycles and the results were unpredictable. It might be
> better to simply buy a larger main jet from Bing if you feel the
> need. I've heard you can do it with flow testing but I figured it
> wasn't worth the effort.
>
>
> ----- Original Message ----- From: "Lynn Matteson" <lynnmatt@jps.net>
> To: <jabiruengine-list@matronics.com>
> Sent: Sunday, May 04, 2008 8:06 AM
> Subject: Re: JabiruEngine-List: Float Level
>
>
>> <lynnmatt@jps.net>
>>
>> Ron-
>> Did you happen to measure (with a # drill) the 240 main before you
>> installed it? Or for that matter the 220? I measured my 220 and
>> it is .078". I'm thinking of drilling my 220 out, as it seems to
>> be the reason that my EGT's are still up in the 1400's when I've
>> gone to a larger needle jet (twice) and it didn't lower the EGT's.
>>
>> Lynn
>>
>> On Apr 28, 2008, at 5:19 PM, RONAL SMITH wrote:
>>
>>> My understanding is that any EGT temp. 1400 F or below is fine
>>> with the Jabiru 2200 engine. I was getting temps up to 1500, so
>>> I changed the needle jet from 276 to 280 and the main jet from
>>> 220 to 240. Now my high temp in cruise is 1375 with the OAT 65
>>> F or above. My engine is Ser. No. 2030.
>>> Ron Smith
>>> Kitfox 4 with Jabiru 2200
>>> forums.matronics.com_-
>>> ============================================================ _-
>>> contribution_-
>>> ===========================================================
>>
>>
>>
>
>
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