Today's Message Index:
----------------------
1. 01:56 PM - Color tune plug for Idle mixture (LarryMcFarland)
2. 03:06 PM - Re: Color tune plug for Idle mixture (Hinde, Frank George (Corvallis))
3. 04:33 PM - Re: Color tune plug for Idle mixture (LarryMcFarland)
4. 05:36 PM - Re: Color tune plug for Idle mixture (Hinde, Frank George (Corvallis))
Message 1
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| Subject: | Color tune plug for Idle mixture |
--> Stratus-List message posted by: LarryMcFarland <larry@macsmachine.com>
Hi guys,
About 2-years ago, I wrote a lengthy post here on jetting the Stratus
Subaru with Bings and I had maneuvered thru mixture adjustments using
EGT sensors and a Grand Rapids Technologies Engine Information System.
It was intended that further mixture corrections would be resolved by
simply reading the EGT temps. I forgot that Id purchased a Color-Tune
plug that enabled seeing the actual flame within the chamber. Seemed
redundant with engine running fine of late. Today the color tune plug
was used and I was surprised to be so mistaken.
Spark plugs have always seemed sooty at idle rpms, so this afternoon, I
removed the prop, replaced the front #1 plug with the Color-Tune plug
and connected the plug wire. The engine had been warmed a few minutes
earlier so it fired and ran a little roughly at 1000 rpm. I saw the
orange glow thru the glass in the plug and began turning the idle
mixture screw until the glow had changed to a bright blue. The engine
seemed to run a little better at the low rpm. This was repeated on the
opposite front plug as it also was unsteadily flashing orange and I
adjusted the idle mixture screw to a steady blue flame.
Again, on the rear plug, the process was repeated and I was surprised to
see a bit of orange flashing in the chamber. A slight adjustment brought
the rear plug to a constant blue fire. The opposing rear plug was done
the same way with the same results. The front plugs were checked again
and all were blue and the engine was ticking along smoothly even better
than its ever run at idle. What a difference!
Anyway, the first of this series was a 1000-rpm test for setting idle
mixture and Im awaiting a 2.78 one-size larger mid range jet for the
2000-rpm test and a #178 one size larger main jet for a 3000-rpm test.
Ive been comfortable that EGT temps have stayed near 1400, but now Im
convinced the engine EGTs might be able to run even cooler.
Will post again when the jets arrive and the next set of rpms are run.
Fly safe,
Larry McFarland 601HDS at www.macsmachine.com
Message 2
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| Subject: | Color tune plug for Idle mixture |
--> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
I can confirm color tune is awesome for setting up idle mixture. I did
the same.
Beware the prop spinning next to your ear of course...:)
Frank
-----Original Message-----
From: owner-stratus-list-server@matronics.com
[mailto:owner-stratus-list-server@matronics.com] On Behalf Of
LarryMcFarland
Sent: Saturday, March 25, 2006 1:56 PM
Subject: Stratus-List: Color tune plug for Idle mixture
--> Stratus-List message posted by: LarryMcFarland
--> <larry@macsmachine.com>
Hi guys,
About 2-years ago, I wrote a lengthy post here on jetting the Stratus
Subaru with Bings and I had maneuvered thru mixture adjustments using
EGT sensors and a Grand Rapids Technologies Engine Information System.
It was intended that further mixture corrections would be resolved by
simply reading the EGT temps. I forgot that Id purchased a Color-Tune
plug that enabled seeing the actual flame within the chamber. Seemed
redundant with engine running fine of late. Today the color tune plug
was used and I was surprised to be so mistaken.
Spark plugs have always seemed sooty at idle rpms, so this afternoon, I
removed the prop, replaced the front #1 plug with the Color-Tune plug
and connected the plug wire. The engine had been warmed a few minutes
earlier so it fired and ran a little roughly at 1000 rpm. I saw the
orange glow thru the glass in the plug and began turning the idle
mixture screw until the glow had changed to a bright blue. The engine
seemed to run a little better at the low rpm. This was repeated on the
opposite front plug as it also was unsteadily flashing orange and I
adjusted the idle mixture screw to a steady blue flame.
Again, on the rear plug, the process was repeated and I was surprised to
see a bit of orange flashing in the chamber. A slight adjustment brought
the rear plug to a constant blue fire. The opposing rear plug was done
the same way with the same results. The front plugs were checked again
and all were blue and the engine was ticking along smoothly even better
than its ever run at idle. What a difference!
Anyway, the first of this series was a 1000-rpm test for setting idle
mixture and Im awaiting a 2.78 one-size larger mid range jet for the
2000-rpm test and a #178 one size larger main jet for a 3000-rpm test.
Ive been comfortable that EGT temps have stayed near 1400, but now Im
convinced the engine EGTs might be able to run even cooler.
Will post again when the jets arrive and the next set of rpms are run.
Fly safe,
Larry McFarland 601HDS at www.macsmachine.com
Message 3
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| Subject: | Re: Color tune plug for Idle mixture |
--> Stratus-List message posted by: LarryMcFarland <larry@macsmachine.com>
Frank,
I won't work on a running Subaru engine with a propeller on. I get
heartburn just thinking about it!
Only takes 15 minutes to take it off and another 20 to put it back on.
You can't do that with a Lyc
of course.
Larry
Hinde, Frank George (Corvallis) wrote:
>--> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
>
>I can confirm color tune is awesome for setting up idle mixture. I did
>the same.
>
>Beware the prop spinning next to your ear of course...:)
>
>Frank
>
>
>
Message 4
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| Subject: | Color tune plug for Idle mixture |
--> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Oh I did all my tuning (color tune and hi speed timing) with the prop
on...Gets the adrenalin going...:)
Frank
-----Original Message-----
From: owner-stratus-list-server@matronics.com
[mailto:owner-stratus-list-server@matronics.com] On Behalf Of
LarryMcFarland
Sent: Saturday, March 25, 2006 4:33 PM
Subject: Re: Stratus-List: Color tune plug for Idle mixture
--> Stratus-List message posted by: LarryMcFarland
--> <larry@macsmachine.com>
Frank,
I won't work on a running Subaru engine with a propeller on. I get
heartburn just thinking about it!
Only takes 15 minutes to take it off and another 20 to put it back on.
You can't do that with a Lyc
of course.
Larry
Hinde, Frank George (Corvallis) wrote:
>--> Stratus-List message posted by: "Hinde, Frank George (Corvallis)"
>--> <frank.hinde@hp.com>
>
>I can confirm color tune is awesome for setting up idle mixture. I did
>the same.
>
>Beware the prop spinning next to your ear of course...:)
>
>Frank
>
>
>
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