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Engine Stumble on Climb Out

 
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ggtyler



Joined: 05 Mar 2016
Posts: 25

PostPosted: Wed May 30, 2018 10:44 pm    Post subject: Engine Stumble on Climb Out Reply with quote

Just a bit of excitement in the Yak 52TW today.

Flight before last the engine did a hard stumble twice in succession on climb out. I immediately swung back towards the field, but once I pulled back from 2400RPM to 2100, it smoothed out. Gave it a few minutes, played with the throttle and rpm's and it did not come back. Figured it was just a fouled plug.

I did a couple more hours of flying and starts/stops that day with no issues.

Went up again today, and on climb out, 2400 RPM, hard stumble. Then another, and another, quickly turned back, pulled back to 2100 RPM, but the hard stumbles proceeded to keep happening. At one point, I was pretty sure it was going to quit running entirely. That 1.5 seconds or 2 seconds of stumbles in a row can feel like an eternity.

It was running pretty badly, wife was in the back on her second flight ever with me. I was pretty darn stressed, so more focused on getting back on the ground safely than anything else. I did not think to do a mag check, but didn't really have time, as I had only just made pattern altitude by the time I was on downwind. I did scan through all the instruments, and all temps/pressures seemed be normal.

On final, I must say, I just wanted us to be back on the ground NOW, and was getting in a bit of a hurry to get down. Realizing that stress was dictating my landing, I just kept telling myself "don't get in a hurry, hold it off, hold it off". Not my best landing ever, but not one I need to be ashamed of. I did find it hard to keep my legs from bouncing all over while taxing. Not often I get that much adrenaline pumping.

Wife's a bit of a gear-head so knew everything was definitely not cool, but she stayed calm and didn't freak out. It's nice to have someone to hug after a bit of a scare.

Dropped a text to Vladimir Yastremski (he does my annuals). That guy always calls me back, no matter what time of day. He's even on vacation right now. Talk about service! Diagnostics will come later, and will update here.


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Looigi



Joined: 20 Apr 2015
Posts: 77
Location: Christchurch, New Zealand

PostPosted: Wed May 30, 2018 11:01 pm    Post subject: Re: Engine Stumble on Climb Out Reply with quote

Hi there,

We had exactly the same fault on ours a few months ago. I found that one of our magneto coils had an intermittent open circuit.

Have a measure of the resistance through the electrode of your spark plugs. I will be that at least one of them will have a high resistance. They should measure 1000-1500 ohms.

I will be happy to skype and chat through my findings if that helps you out.

Regards
Chris


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richard.goode(at)russiana
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PostPosted: Thu May 31, 2018 12:24 am    Post subject: Engine Stumble on Climb Out Reply with quote

This is a classic symptom of coil failure - we have seen it on over 30
different aircraft over the years! Typically it is always heat -related.
That is, with a cold engine, it will run perfectly with normal small
magneto-drop. But when the engine warms up (normally 20/30 minutes after
take-off), and heat soaks through to the magneto, the coil begins to break
down. The problem is exacerbated because of the design of the coil in which
the condenser (and it seems to be the condenser that fails) is inside the
coil, and so the heat from the wire coil warms the condenser that much more
than the temperature of the inside of the magneto.

We have spent a lot of time researching the issue, and now make coils with
the condenser bonded externally to the coil, but it is relatively small and
does not affect mounting the coil. Also, with the external condenser, we are
finding that the magnetos give a stronger spark from very low rpm.

Finally, it is worth saying that we test every magneto and indeed each coil
in a high-temperature test cell for a minimum of two hours where the magneto
is heated to a higher temperature than it would ever encounter during
flight, the obvious aim being to check that the magneto/oil not going to
fail in service.

Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW

Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com

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PostPosted: Fri Jun 01, 2018 7:40 am    Post subject: Engine Stumble on Climb Out Reply with quote

Not exactly a Yak, but has a bit of Yak dna.
https://www.auctionzip.com/auction-lot/lot_C5F405A9AF?utm_source=azemail&utm_medium=email&utm_campaign=alerts
On Wed, May 30, 2018 at 11:44 PM, ggtyler <ggtyler(at)gmail.com (ggtyler(at)gmail.com)> wrote:
Quote:
--> Yak-List message posted by: "ggtyler" <ggtyler(at)gmail.com (ggtyler(at)gmail.com)>

Just a bit of excitement in the Yak 52TW today.

Flight before last the engine did a hard stumble twice in succession on climb out. I immediately swung back towards the field, but once I pulled back from 2400RPM to 2100, it smoothed out. Gave it a few minutes, played with the throttle and rpm's and it did not come back. Figured it was just a fouled plug.

I did a couple more hours of flying and starts/stops that day with no issues.

Went up again today, and on climb out, 2400 RPM, hard stumble. Then another, and another, quickly turned back, pulled back to 2100 RPM, but the hard stumbles proceeded to keep happening. At one point, I was pretty sure it was going to quit running entirely. That 1.5 seconds or 2 seconds of stumbles in a row can feel like an eternity.

It was running pretty badly, wife was in the back on her second flight ever with me. I was pretty darn stressed, so more focused on getting back on the ground safely than anything else. I did not think to do a mag check, but didn't really have time, as I had only just made pattern altitude by the time I was  on downwind. I did scan through all the instruments, and all temps/pressures seemed be normal.

On final, I must say, I just wanted us to be back on the ground NOW, and was getting in a bit of a hurry to get down. Realizing that stress was dictating my landing, I just kept telling myself "don't get in a hurry, hold it off, hold it off". Not my best landing ever, but not one I need to be ashamed of. I did find it hard to keep my legs from bouncing all over while taxing. Not often I get that much adrenaline pumping.

Wife's a bit of a gear-head so knew everything was definitely not cool, but she stayed calm and didn't freak out. It's nice to have someone to hug after a bit of a scare.

Dropped a text to Vladimir Yastremski (he does my annuals). That guy always calls me back, no matter what time of day. He's even on vacation right now. Talk about service! Diagnostics will come later, and will update here.




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PostPosted: Mon Jun 04, 2018 4:51 am    Post subject: Engine Stumble on Climb Out Reply with quote

Holy double props Sappman...

Quote:
On June 1, 2018 at 10:40 AM doug sapp <dougsappllc(at)gmail.com> wrote:

Not exactly a Yak, but has a bit of Yak dna.
https://www.auctionzip.com/auction-lot/lot_C5F405A9AF?utm_source=azemail&utm_medium=email&utm_campaign=alerts
On Wed, May 30, 2018 at 11:44 PM, ggtyler <ggtyler(at)gmail.com (ggtyler(at)gmail.com)> wrote:
Quote:
--> Yak-List message posted by: "ggtyler" <ggtyler(at)gmail.com (ggtyler(at)gmail.com)>

Just a bit of excitement in the Yak 52TW today.

Flight before last the engine did a hard stumble twice in succession on climb out. I immediately swung back towards the field, but once I pulled back from 2400RPM to 2100, it smoothed out. Gave it a few minutes, played with the throttle and rpm's and it did not come back. Figured it was just a fouled plug.

I did a couple more hours of flying and starts/stops that day with no issues.

Went up again today, and on climb out, 2400 RPM, hard stumble. Then another, and another, quickly turned back, pulled back to 2100 RPM, but the hard stumbles proceeded to keep happening. At one point, I was pretty sure it was going to quit running entirely. That 1.5 seconds or 2 seconds of stumbles in a row can feel like an eternity.

It was running pretty badly, wife was in the back on her second flight ever with me. I was pretty darn stressed, so more focused on getting back on the ground safely than anything else. I did not think to do a mag check, but didn't really have time, as I had only just made pattern altitude by the time I was  on downwind. I did scan through all the instruments, and all temps/pressures seemed be normal.

On final, I must say, I just wanted us to be back on the ground NOW, and was getting in a bit of a hurry to get down. Realizing that stress was dictating my landing, I just kept telling myself "don't get in a hurry, hold it off, hold it off". Not my best landing ever, but not one I need to be ashamed of. I did find it hard to keep my legs from bouncing all over while taxing. Not often I get that much adrenaline pumping.

Wife's a bit of a gear-head so knew everything was definitely not cool, but she stayed calm and didn't freak out. It's nice to have someone to hug after a bit of a scare.

Dropped a text to Vladimir Yastremski (he does my annuals). That guy always calls me back, no matter what time of day. He's even on vacation right now. Talk about service! Diagnostics will come later, and will update here.




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PostPosted: Mon Jun 04, 2018 5:49 am    Post subject: Engine Stumble on Climb Out Reply with quote

Could very well be the infamous magneto coil issue.

A. Dennis Savarese
334-546-8182 (mobile)
www.yak-52.com
Skype - Yakguy1

On 6/4/2018 8:51 AM, JON BLAKE wrote:
Quote:
Holy double props Sappman...

> On June 1, 2018 at 10:40 AM doug sapp <dougsappllc(at)gmail.com> wrote:
>
> Not exactly a Yak, but has a bit of Yak dna.
> https://www.auctionzip.com/auction-lot/lot_C5F405A9AF?utm_source=azemail&utm_medium=email&utm_campaign=alerts
>
> On Wed, May 30, 2018 at 11:44 PM, ggtyler <ggtyler(at)gmail.com
> <mailto:ggtyler(at)gmail.com>> wrote:
>
>
> <mailto:ggtyler(at)gmail.com>>
>
> Just a bit of excitement in the Yak 52TW today.
>
> Flight before last the engine did a hard stumble twice in
> succession on climb out. I immediately swung back towards the
> field, but once I pulled back from 2400RPM to 2100, it smoothed
> out. Gave it a few minutes, played with the throttle and rpm's
> and it did not come back. Figured it was just a fouled plug.
>
> I did a couple more hours of flying and starts/stops that day
> with no issues.
>
> Went up again today, and on climb out, 2400 RPM, hard stumble.
> Then another, and another, quickly turned back, pulled back to
> 2100 RPM, but the hard stumbles proceeded to keep happening. At
> one point, I was pretty sure it was going to quit running
> entirely. That 1.5 seconds or 2 seconds of stumbles in a row can
> feel like an eternity.
>
> It was running pretty badly, wife was in the back on her second
> flight ever with me. I was pretty darn stressed, so more focused
> on getting back on the ground safely than anything else. I did
> not think to do a mag check, but didn't really have time, as I
> had only just made pattern altitude by the time I was  on
> downwind. I did scan through all the instruments, and all
> temps/pressures seemed be normal.
>
> On final, I must say, I just wanted us to be back on the ground
> NOW, and was getting in a bit of a hurry to get down. Realizing
> that stress was dictating my landing, I just kept telling myself
> "don't get in a hurry, hold it off, hold it off". Not my best
> landing ever, but not one I need to be ashamed of. I did find it
> hard to keep my legs from bouncing all over while taxing. Not
> often I get that much adrenaline pumping.
>
> Wife's a bit of a gear-head so knew everything was definitely not
> cool, but she stayed calm and didn't freak out. It's nice to have
> someone to hug after a bit of a scare.
>
> Dropped a text to Vladimir Yastremski (he does my annuals). That
> guy always calls me back, no matter what time of day. He's even
> on vacation right now. Talk about service! Diagnostics will come
> later, and will update here.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=480530#480530
> <http://forums.matronics.com/viewtopic.php?p=480530#480530>
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>           -Matt Dralle, List Admin.
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contribution
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Viperdoc



Joined: 19 Apr 2014
Posts: 465
Location: 08A

PostPosted: Mon Jun 04, 2018 5:56 am    Post subject: Engine Stumble on Climb Out Reply with quote

Bad mag coil.Doc

Sent from my iPad

On Jun 4, 2018, at 7:51 AM, JON BLAKE <jblake207(at)comcast.net (jblake207(at)comcast.net)> wrote:
Quote:
Holy double props Sappman...

Quote:
On June 1, 2018 at 10:40 AM doug sapp <dougsappllc(at)gmail.com (dougsappllc(at)gmail.com)> wrote:

Not exactly a Yak, but has a bit of Yak dna.
https://www.auctionzip.com/auction-lot/lot_C5F405A9AF?utm_source=azemail&utm_medium=email&utm_campaign=alerts
On Wed, May 30, 2018 at 11:44 PM, ggtyler <ggtyler(at)gmail.com (ggtyler(at)gmail.com)> wrote:
Quote:
--> Yak-List message posted by: "ggtyler" <ggtyler(at)gmail.com (ggtyler(at)gmail.com)>

Just a bit of excitement in the Yak 52TW today.

Flight before last the engine did a hard stumble twice in succession on climb out. I immediately swung back towards the field, but once I pulled back from 2400RPM to 2100, it smoothed out. Gave it a few minutes, played with the throttle and rpm's and it did not come back. Figured it was just a fouled plug.

I did a couple more hours of flying and starts/stops that day with no issues.

Went up again today, and on climb out, 2400 RPM, hard stumble. Then another, and another, quickly turned back, pulled back to 2100 RPM, but the hard stumbles proceeded to keep happening. At one point, I was pretty sure it was going to quit running entirely. That 1.5 seconds or 2 seconds of stumbles in a row can feel like an eternity.

It was running pretty badly, wife was in the back on her second flight ever with me. I was pretty darn stressed, so more focused on getting back on the ground safely than anything else. I did not think to do a mag check, but didn't really have time, as I had only just made pattern altitude by the time I was on downwind. I did scan through all the instruments, and all temps/pressures seemed be normal.

On final, I must say, I just wanted us to be back on the ground NOW, and was getting in a bit of a hurry to get down. Realizing that stress was dictating my landing, I just kept telling myself "don't get in a hurry, hold it off, hold it off". Not my best landing ever, but not one I need to be ashamed of. I did find it hard to keep my legs from bouncing all over while taxing. Not often I get that much adrenaline pumping.

Wife's a bit of a gear-head so knew everything was definitely not cool, but she stayed calm and didn't freak out. It's nice to have someone to hug after a bit of a scare.

Dropped a text to Vladimir Yastremski (he does my annuals). That guy always calls me back, no matter what time of day. He's even on vacation right now. Talk about service! Diagnostics will come later, and will update here.




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Looigi



Joined: 20 Apr 2015
Posts: 77
Location: Christchurch, New Zealand

PostPosted: Mon Jun 04, 2018 2:41 pm    Post subject: Re: Engine Stumble on Climb Out Reply with quote

So, I pulled the plus on my Yak-52 today as a part of the Annual check and measured the resistance through the core (plug lead contact to electrode). I found a varied set of resistance values ranging from 1500 ohms (perfect) through 5000 ohms (the accepted limit) to 15 000 ohms (way outside tolerance).

I have replaced one magneto coil and two starter booster coils on my plane in 70 hours! I doubt that these parts are the root cause. My suspicion is that the high resistance plugs are causing the issues we are seeing. I think what is happening is that the spark energy is cross firing inside the harness to a cylinder that is on it's induction stroke rather than go through the high resistance plugs like a well behaved spark should. The rogue spark energy could also me damaging the capacitor in the coil as well, like Richard suggests.

I have asked before, but I have not had any replies... What are the resistance of your plugs? I'll bet that you have a few high resistance plugs in amongst yours.

We are going to be fitting Dennis's automotive kit to our Yak to hopefully resolve this issue.

There is some serious Yak and CJ-6 experience on here... Thoughts?

Chris


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PostPosted: Mon Jun 04, 2018 3:38 pm    Post subject: Engine Stumble on Climb Out Reply with quote

Go with Dennis’s kit by all means.

Frank

Sent from my iPhone

Quote:
On Jun 4, 2018, at 3:41 PM, Looigi <cdoburton(at)gmail.com> wrote:



So, I pulled the plus on my Yak-52 today as a part of the Annual check and measured the resistance through the core (plug lead contact to electrode). I found a varied set of resistance values ranging from 1500 ohms (perfect) through 5000 ohms (the accepted limit) to 15 000 ohms (way outside tolerance).

I have replaced one magneto coil and two starter booster coils on my plane in 70 hours! I doubt that these parts are the root cause. My suspicion is that the high resistance plugs are causing the issues we are seeing. I think what is happening is that the spark energy is cross firing inside the harness to a cylinder that is on it's induction stroke rather than go through the high resistance plugs like a well behaved spark should. The rogue spark energy could also me damaging the capacitor in the coil as well, like Richard suggests.

I have asked before, but I have not had any replies... What are the resistance of your plugs? I'll bet that you have a few high resistance plugs in amongst yours.

We are going to be fitting Dennis's automotive kit to our Yak to hopefully resolve this issue.

There is some serious Yak and CJ-6 experience on here... Thoughts?

Chris




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http://forums.matronics.com/viewtopic.php?p=480649#480649











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PostPosted: Mon Jun 04, 2018 3:38 pm    Post subject: Engine Stumble on Climb Out Reply with quote

As far as the stumble you experienced, although you replaced one coil already, don't discount the fact that the other mag coil could also be failing intermittently.

There is another very important issue that many, many people do not look into. It is much like setting the E gap on a Bendix or Slick magneto used on a Lycoming or Continental engine. All of the Russian and Chinese mags have the same issue and that is, there is no E-gap setting. The E-gap setting on the Bendix or Slick magnetos sets the point gap AND aligns the rotor finger with the contact point in the distributor cap.

Most everyone understands that the point gap has to be set to .25-.35mm or .010-.014 thousands. Ideally, .3 mm or .012. But again, setting the point gap does not align the rotor to the contact point to the distributor cap on the Russian and Chinese mags. And that is where so many people setting the timing on the Russian and Chinese mags fall short. It is imperative after setting the point gap and the timing that the rotor be properly positioned when the points first open on the number 4 cylinder, to align directly under the distributor contact point. That is why there are 3 slots in the rotor with screws so the screws can be loosened and the leading finger in the counterclockwise rotation points directly to the scribe mark on the flat surface mating with the cover and next to the high voltage stick. Loosen the 3 screws and with a 6" metal ruler or straight edge, align the straight edge with the center of the rotor, the leading finger in the counterclockwise rotation direction AND the scribe mark. Be sure to look directly down on the magneto. Not on an angle because the alignment will not be directly under the contact point when the distributor cap is reinstalled. Once you do this, you will have essentially set the "E-gap" and eliminate any potential arcing between the rotor finger and the contact in the cap. Remember, ANY air gap adds resistance to the circuit and thus reduces the electrical charge to the plug. That is why positioning the rotor after setting the point gap and then the mag timing is so important.
Dennis


From: Looigi <cdoburton(at)gmail.com>
To: yak-list(at)matronics.com
Sent: Monday, June 4, 2018 6:44 PM
Subject: Re: Engine Stumble on Climb Out


--> Yak-List message posted by: "Looigi" <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>

So, I pulled the plus on my Yak-52 today as a part of the Annual check and measured the resistance through the core (plug lead contact to electrode). I found a varied set of resistance values ranging from 1500 ohms (perfect) through 5000 ohms (the accepted limit) to 15 000 ohms (way outside tolerance).

I have replaced one magneto coil and two starter booster coils on my plane in 70 hours! I doubt that these parts are the root cause. My suspicion is that the high resistance plugs are causing the issues we are seeing. I think what is happening is that the spark energy is cross firing inside the harness to a cylinder that is on it's induction stroke rather than go through the high resistance plugs like a well behaved spark should. The rogue spark energy could also me damaging the capacitor in the coil as well, like Richard suggests.

I have asked before, but I have not had any replies... What are the resistance of your plugs? I'll bet that you have a few high resistance plugs in amongst yours.

We are going to be fitting Dennis's automotive kit to our Yak to hopefully resolve this issue.

There is some serious Yak and CJ-6 experience on here... Thoughts?

Chris

Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=480649#480649

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PostPosted: Mon Jun 04, 2018 6:34 pm    Post subject: Engine Stumble on Climb Out Reply with quote

Dennis,

An excellent point and very well explained! – a good refresher for many of us, myself included…

Thanks much,

Sam Sax
Miami

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of A. Dennis Savarese
Sent: Monday, June 04, 2018 7:38 PM
To: yak-list(at)matronics.com
Subject: Re: Re: Engine Stumble on Climb Out

As far as the stumble you experienced, although you replaced one coil already, don't discount the fact that the other mag coil could also be failing intermittently.



There is another very important issue that many, many people do not look into. It is much like setting the E gap on a Bendix or Slick magneto used on a Lycoming or Continental engine. All of the Russian and Chinese mags have the same issue and that is, there is no E-gap setting. The E-gap setting on the Bendix or Slick magnetos sets the point gap AND aligns the rotor finger with the contact point in the distributor cap.



Most everyone understands that the point gap has to be set to .25-.35mm or .010-.014 thousands. Ideally, .3 mm or .012. But again, setting the point gap does not align the rotor to the contact point to the distributor cap on the Russian and Chinese mags. And that is where so many people setting the timing on the Russian and Chinese mags fall short. It is imperative after setting the point gap and the timing that the rotor be properly positioned when the points first open on the number 4 cylinder, to align directly under the distributor contact point. That is why there are 3 slots in the rotor with screws so the screws can be loosened and the leading finger in the counterclockwise rotation points directly to the scribe mark on the flat surface mating with the cover and next to the high voltage stick. Loosen the 3 screws and with a 6" metal ruler or straight edge, align the straight edge with the center of the rotor, the leading finger in the counterclockwise rotation direction AND the scribe mark. Be sure to look directly down on the magneto. Not on an angle because the alignment will not be directly under the contact point when the distributor cap is reinstalled. Once you do this, you will have essentially set the "E-gap" and eliminate any potential arcing between the rotor finger and the contact in the cap. Remember, ANY air gap adds resistance to the circuit and thus reduces the electrical charge to the plug. That is why positioning the rotor after setting the point gap and then the mag timing is so important.

Dennis


From: Looigi <cdoburton(at)gmail.com>
To: yak-list(at)matronics.com
Sent: Monday, June 4, 2018 6:44 PM
Subject: Re: Engine Stumble on Climb Out


--> Yak-List message posted by: "Looigi" <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>



So, I pulled the plus on my Yak-52 today as a part of the Annual check and measured the resistance through the core (plug lead contact to electrode). I found a varied set of resistance values ranging from 1500 ohms (perfect) through 5000 ohms (the accepted limit) to 15 000 ohms (way outside tolerance).



I have replaced one magneto coil and two starter booster coils on my plane in 70 hours! I doubt that these parts are the root cause. My suspicion is that the high resistance plugs are causing the issues we are seeing. I think what is happening is that the spark energy is cross firing inside the harness to a cylinder that is on it's induction stroke rather than go through the high resistance plugs like a well behaved spark should. The rogue spark energy could also me damaging the capacitor in the coil as well, like Richard suggests.



I have asked before, but I have not had any replies... What are the resistance of your plugs? I'll bet that you have a few high resistance plugs in amongst yours.



We are going to be fitting Dennis's automotive kit to our Yak to hopefully resolve this issue.



There is some serious Yak and CJ-6 experience on here... Thoughts?



Chris









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wlannon(at)shaw.ca
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PostPosted: Mon Jun 04, 2018 6:48 pm    Post subject: Engine Stumble on Climb Out Reply with quote

I have been checking aircraft spark plug resistance for a few years now.

My score so far: Champion -- Terrible, Tempest -- Very good, Chinese DZ
5 -- The best, typically 1200 -1500. Don't recall ever replacing one for
this reason. Have not, so far, checked any Russian ones.

Walt

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PostPosted: Mon Jun 04, 2018 7:04 pm    Post subject: Engine Stumble on Climb Out Reply with quote

My limited experience with the Chinese DZ5 plugs is the are hotter.
Doc

Sent from my iPad

[quote] On Jun 4, 2018, at 9:48 PM, Walter Lannon <wlannon(at)shaw.ca> wrote:



I have been checking aircraft spark plug resistance for a few years now.

My score so far: Champion -- Terrible, Tempest -- Very good, Chinese DZ 5 -- The best, typically 1200 -1500. Don't recall ever replacing one for this reason. Have not, so far, checked any Russian ones.

Walt

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vookis
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PostPosted: Mon Feb 25, 2019 1:24 am    Post subject: Re: Engine Stumble on Climb Out Reply with quote

I can not do this calm, because I feel great excitement. I can do nothing with myself. It may be worth taking medications, such as ambien for example? Someone was treating excitement with pills? Tell me about your experience. I have a lot of problems because of my excitement, it is very difficult for me to live with it. Maybe I should contact a psychologist?

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PostPosted: Mon Feb 25, 2019 11:53 am    Post subject: Engine Stumble on Climb Out Reply with quote

Ok, well this sure took the Yak List into a whole new category!

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hill(at)doctor-hill.com
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PostPosted: Mon Feb 25, 2019 12:23 pm    Post subject: Engine Stumble on Climb Out Reply with quote

The list was obviously hacked.

[quote] On Feb 25, 2019, at 12:52 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:



Ok, well this sure took the Yak List into a whole new category!

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