What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Lightspeed Plasma III problem

MSFT-1

MSFT-1

Well Known Member
I have an RV-10 with a Mattituck Red/Gold IO-540 that has a Lightspeed Engineering Plasma III on one set of plugs and a traditional magneto on the other set.

I recently noticed an abnormal drop in the RPMs when I switch to just the Plasma. I checked the EGT and it showed that cylinders 3 and 4 are not firing when only the Plasma III is on. When I switch back to the mag or both, those cylinders immediately come back up to the appropriate temperature.

Cylinders 3 and 4 are driven by the same coil in the LSE design so I suspect that the coil has gone bad.

I am planning to order another one tomorrow. I have downed the airplane while waiting for the part.

I am wondering how the reliability of the LSE has been for other people. This one has been problem free for 18 months so I am not particularly upset. A coil costs $79 so it seems that having an extra one might be a good idea.

Does my diagnosis sound right? Any thoughts or guidance from engine experts?

Thanks
 
The only things left seem to be the connectors at the coil, the connector at the controller, and the wire inbetween.
 
Before you invest in a new coil, why not swap the two coils and make sure it is not the bain box or the connections?
 
MSFT-1 said:
I have an RV-10 with a Mattituck Red/Gold IO-540 that has a Lightspeed Engineering Plasma III on one set of plugs and a traditional magneto on the other set.

I recently noticed an abnormal drop in the RPMs when I switch to just the Plasma. I checked the EGT and it showed that cylinders 3 and 4 are not firing when only the Plasma III is on. When I switch back to the mag or both, those cylinders immediately come back up to the appropriate temperature.

Cylinders 3 and 4 are driven by the same coil in the LSE design so I suspect that the coil has gone bad.

I am planning to order another one tomorrow. I have downed the airplane while waiting for the part.

I am wondering how the reliability of the LSE has been for other people. This one has been problem free for 18 months so I am not particularly upset. A coil costs $79 so it seems that having an extra one might be a good idea.

Does my diagnosis sound right? Any thoughts or guidance from engine experts?

Thanks
Click to expand...

The LSE Plasma 111 is not as reliable as the Plasma 11. The longer spark duration places higher stresses on the ignition coils.

But builders continue to buy the Plasma 111 because of the "Spinal tap theory"......a higher number must be better.
 
Captain Avgas said:
The LSE Plasma 111 is not as reliable as the Plasma 11. The longer spark duration places higher stresses on the ignition coils.

But builders continue to buy the Plasma 111 because of the "Spinal tap theory"......a higher number must be better.
Click to expand...

That's a new one to me; I hope you're wrong. I have trouble understanding how a coil can fail, anyway - it's just a bunch of windings of wire. Unless heat destroys the insulation...

Flew 400 hrs on my last plane with a II and no problems; this plane has a III and no problems yet either. Most of the issues I've heard of are either poor cooling or bad connectors.

If cooling is the issue, perhaps mounting them in or near the inlets would be a good idea?
 
AFAIK, the Plasma III is the only one offered by Mattituck

I agree that most people (including me) assume the higher number means a better (or at least newer) product.

In this case though, I think the Plasma II is not available as an option on the Mattituck Red/Gold.
 
Verify the wire connections on that coil. Also unplug and reseat the connectors into the box. I had a problem once not unlike yours (best recollection) and swapping out things did not result in a failed unit.

My guess is that corrosion on the connectors was cleaned by the removal and reseating of the connectors.
 
Captain Avgas said:
The LSE Plasma 111 is not as reliable as the Plasma 11. The longer spark duration places higher stresses on the ignition coils.

But builders continue to buy the Plasma 111 because of the "Spinal tap theory"......a higher number must be better.
Click to expand...

Can you defend that first statement with facts? Not just anecdotes gleaned from the internet. As for the second statement, those are pretty harsh words.
 
plasma III

There is one major functional difference with the III that I am aware of. The sensors are mounted differently on the III than they are on the II. They are mounted in such a way that they are easier to adjust. This is one of the primary differences that has convinced me to go with the III instead of the II.
 
Lars said:
Can you defend that first statement with facts? Not just anecdotes gleaned from the internet. As for the second statement, those are pretty harsh words.
Click to expand...

The anecdotal evidence would suggest that both the Plasma 11 and Plasma 111 are very reliable units and either should provide good service. And properly set up both should offer better reliability than a magneto.

However, by the very nature of its longer duration spark, the Plasma 111 will erode spark plugs faster and place higher stresses on both the high tension wires and coils. In simple terms that means the Plasma 111 will exhibit a decreased MTBF (mean time between failure) compared to the Plasma 11.

Anybody in any doubt on this issue can always refer to the manufacturer. Apart from that, it's logical. The spark plugs, high tension wires, and coils are the same devices in both ignition systems but in the Plasma 111 they're working harder.

It's a bit like opting for high compression pistons on a Lycoming. You get a slight boost in performance but you place an additional stress on the engine that can reduce longevity. In other words there is a small trade in terms of opting for performance as against reliability (or longevity as the case may be).

It's obviously the same for the Lightspeed ignitions. It's a personal decision. It just depends where your priority lies.....a small gain in performance vs a small gain in reliability (whether in fact the Plasma 111 with it's longer duration spark actually provides any real world measurable improvement in performance over the Plasma 11 is perhaps debatable....but that's another story).

I stated that some builders opt for a Plasma 111 over a Plasma 11 purely because they assume the larger number is synonymous with "better". I don't think that is being harsh...it's just a statement of fact and I'm sure that many purchasers of the Plasma 111 would concur.
 
Last edited:
I think the question was fair - if only for my own information I for one would like to see info on what real-world measurements might have been done to evaluate "degradation" in coils, wires, plugs. If not directly on the Lightspeed units, then on similar spark systems.

It might cause me to replace some of these items as "preventive maintenence" at some point.
 
breister said:
I think the question was fair - if only for my own information I for one would like to see info on what real-world measurements might have been done to evaluate "degradation" in coils, wires, plugs. If not directly on the Lightspeed units, then on similar spark systems.

It might cause me to replace some of these items as "preventive maintenence" at some point.
Click to expand...

The typical failure scenario between a "mechanical" ignition (ie. a magneto) and a "solid state" ignition (eg. LightSpeed) is different. Magnetos are most reliable when new....but that is when solid state devices are most failure prone (on a mature electronic device up to 90% of failures occur in the first 10% of time in operation).

In other words it might be said that your magneto, if you have one, is becoming LESS reliable with time....but your LS Plasma 111 is becoming MORE reliable with the passing of flight hours (but is still not as reliable as a Plasma 11) :)
 
Last edited:
Captain Avgas said:
The anecdotal evidence would suggest that both the Plasma 11 and Plasma 111 are very reliable units and either should provide good service. And properly set up both should offer better reliability than a magneto.

However, by the very nature of its longer duration spark, the Plasma 111 will erode spark plugs faster and place higher stresses on both the high tension wires and coils. In simple terms that means the Plasma 111 will exhibit a decreased MTBF (mean time between failure) compared to the Plasma 11.

Anybody in any doubt on this issue can always refer to the manufacturer. Apart from that, it's logical. The spark plugs, high tension wires, and coils are the same devices in both ignition systems but in the Plasma 111 they're working harder.

It's a bit like opting for high compression pistons on a Lycoming. You get a slight boost in performance but you place an additional stress on the engine that can reduce longevity. In other words there is a small trade in terms of opting for performance as against reliability (or longevity as the case may be).

It's obviously the same for the Lightspeed ignitions. It's a personal decision. It just depends where your priority lies.....a small gain in performance vs a small gain in reliability (whether in fact the Plasma 111 with it's longer duration spark actually provides any real world measurable improvement in performance over the Plasma 11 is perhaps debatable....but that's another story).

I stated that some builders opt for a Plasma 111 over a Plasma 11 purely because they assume the larger number is synonymous with "better". I don't think that is being harsh...it's just a statement of fact and I'm sure that many purchasers of the Plasma 111 would concur.
Click to expand...

Fair enough... but if the MTBF of a III is, say, less than 10% below than the II, then while it may be statistically significant, it's probably operationally irrelevant. Especially if the MTBF is up past 1000 hours somewhere. If the MTBF of the II is something like double that of the III, then there would be obviously be more of a cost/benefit argument from an economy vs. reliability perspective. On the other hand, if the MTBF of either is much beyond the engine TBO, then it's probably all irrelevant. Pick the system you like and run it.

Funny- when I asked Klaus Savier to contrast the two systems at Oskosh in 2006, he didn't mention durability or MTBF. But it's not like he had hours of time to talk that day. In any case, I haven't flown with either system, and it sounds like you may have, so I'll defer to you as regards field experience.

My experience is mostly with late model automotive and motorcycle ignition systems (in the latter case my BMW motorcycle has an ignition coil that appears outwardly to be practically identical to the coils sold with the Lightspeed setups) where ignition parts, despite being far more stressed than the automotive & motorcycle systems of 40 years ago, last an insanely long time. I've personally dabbled with auto engine control system mods that imposed heat stresses far beyond stock, and the OEM stuff I'm using still keeps ticking. Amazing.

I still maintain that the tenor of your original reply was calculated more to inflame than to inform. But that's just me...
 
Captain Avgas said:
The typical failure scenario between a "mechanical" ignition (ie. a magneto) and a "solid state" ignition (eg. LightSpeed) is different. Magnetos are most reliable when new....but that is when solid state devices are most failure prone (on a mature electronic device up to 90% of failures occur in the first 10% of time in operation).

In other words it might be said that your magneto, if you have one, is becoming LESS reliable with time....but your LS Plasma 111 is becoming MORE reliable with the passing of flight hours (but is still not as reliable as a Plasma 11) :)
Click to expand...

The high-time Lightspeed failures I've heard of were all coil-related. No fun to lose an ignition in any case, but much easier to carry/replace an ignition coil. My hangar partner just installed dual III's. By the time I'm ready to make a decision I'll have at least one more experiential data point.
 
Lars said:
Funny- when I asked Klaus Savier to contrast the two systems at Oskosh in 2006, he didn't mention durability or MTBF.
Click to expand...

I have always found Klaus to be very honest and candid on technical issues. Perhaps you didn't ask him the right questions.
 
Last edited:
airguy said:
Or perhaps, since he's so honest and candid, there was not an issue to disclose?
Click to expand...

Well, sometimes buyers are so excited about the advertised size of the the donut that they fail to enquire about the size of the hole.

So there is no confusion and I am not misinterpreted, these are my specific statements:

a) The Plasma 11 and 111 are both reliable products. There is no suggestion that either product has an "issue" or "fault".

b) However the Plasma 111 is a less mature product than the Plasma 11.

c) The Plasma 111 has a longer duration spark that will tend to erode spark plugs faster and place higher stresses on high tension wires and ignition coils.

d) As a result of b) and c) one would be better opting for the Plasma 11 over the Plasma 111 if absolute reliability is the sole criterion for the ignition choice.

And I'm absolutely confident that if you bother to ask the people in the industry who know, the people who are supplying and fitting hundreds of these devices, they will tell you exactly the same thing.

So don't take my word for it....go straight to the source and ask Klaus. Or go and ask Bart at AeroSport Power for a truly independent opinion.
 
Last edited:
Captain Avgas said:
Well, sometimes buyers are so excited about the advertised size of the the donut that they fail to enquire about the size of the hole.

So there is no confusion and I am not misinterpreted, these are my specific statements:

a) The Plasma 11 and 111 are both reliable products. There is no suggestion that either product has an "issue" or "fault".

b) However the Plasma 111 is a less mature product than the Plasma 11.

c) The Plasma 111 has a longer duration spark that will tend to erode spark plugs faster and place higher stresses on high tension wires and ignition coils.

d) As a result of b) and c) one would be better opting for the Plasma 11 over the Plasma 111 if absolute reliability is the sole criterion for the ignition choice.

And I'm absolutely confident that if you bother to ask the people in the industry who know, the people who are supplying and fitting hundreds of these devices, they will tell you exactly the same thing.

So don't take my word for it....go straight to the source and ask Klaus. Or go and ask Bart at AeroSport Power for a truly independent opinion.
Click to expand...

In the interest of full disclosure, but full logic, I make the statement that I am neither a buyer (nor operator) of either system, nor do I have any association with the company or product in question.

However (comma)

a) - agreed - there is no evidence that either product is at fault.

b) - This is irrelevant, unless you are strictly looking for a "time in service" grade. In that case, the dinosaurs win, hands down. But have they succeeded?

c) - I can see (and concede) your point on the spark plugs, but this will have no effect whatsoever on the coils or the wires until (and unless) the current flow exceeds the point at which resistance heating overcomes passive heat loss, which has not (to date) been shown to be a factor.

d) - as a result of b) and c) above, is not factually true.

Please note that I am not cheerleading for ANY type of device or manufacturer, merely for physics and facts. Let's keep it real.
 
Last edited:
airguy said:
c) - I can see (and concede) your point on the spark plugs, but this will have no effect whatsoever on the coils or the wires until (and unless) the current flow exceeds the point at which resistance heating overcomes passive heat loss, which has not (to date) been shown to be a factor.
Click to expand...

You are totally incorrect on this. Where are you getting your information from? The failure rate on the Plasma 111 units, including failed ignition coils, is higher than on the Plasma 11 units. LightSpeed themselves acknowledge this fact (if you bother to ask them...which I did).

I also had extensive discussions on this specific subject with one of the most respected (and largest) Experimental engine builders in the market place (a company that has installed literally hundreds of these units) and they confirmed the same information.

So here you have the manufacturer, and major installers, saying the same thing. If reliability is your prime objective then the Plasma 11 is the unit of choice.

For the life of me I cannot understand why people continue to shoot from the lip on this topic without even consulting the manufacturer to get their facts straight.
 
Last edited:
Don't really want to get invloved in this "debate" but I've been running both an LSII for about 900 hrs and a III for about 500 hrs, I've had one or two issues with the II and my buddy had an issue with his II that I helped him with (box problems in all cases) but the III has been trouble free to date.

I believe MTBF is more dependent on design, build and component quality than the measure of output power alone. Not much to go wrong with coils unless they can't take the heat/stress, wires and plugs are normal maintenance items that should be replaced every so often prior to "failure" so they don't count.

I've have also talked to Klaus quite a bit both on the phone and at Osh about II vs III & the problems I've seen with the II, he indicated that there was absolutely no evidence that one was more reliable than the other and he was adament that the III was the better unit. When I installed the III and dumped the second mag I was looking for maximum reliability and I could find no evidence to support that the II was more reliable than the III other than the II has been around longer.

Just my 2c for what it's worth
 
I have a III (and a mag) and when I decided to use it, my decision was based on advice from Klaus. Reliability wasn't discussed because I didn't realize there was a difference. Klaus told me that with a carburetor a Plasma III may be slightly better in terms of fuel economy and leaning because of the inherrant uneveness of fuel/air distribution between cylinders (with a carb). The longer duration spark would help the slightly richer cylinders burn their extra fuel and in a way help balance things out a little - 'least that's what I think he said in general. I only have a little over 80 hours so reliability is not an issue yet. I plan on buying new spark plugs for the EI every 100 hours or so if they look a little worn. They're cheap enough.

Scott
RV-8 FB
 
Walt said:
Don't really want to get invloved in this "debate" but I've been running both an LSII for about 900 hrs and a III for about 500 hrs, I've had one or two issues with the II and my buddy had an issue with his II that I helped him with (box problems in all cases) but the III has been trouble free to date.

I believe MTBF is more dependent on design, build and component quality than the measure of output power alone. Not much to go wrong with coils unless they can't take the heat/stress, wires and plugs are normal maintenance items that should be replaced every so often prior to "failure" so they don't count.

I've have also talked to Klaus quite a bit both on the phone and at Osh about II vs III & the problems I've seen with the II, he indicated that there was absolutely no evidence that one was more reliable than the other and he was adament that the III was the better unit. When I installed the III and dumped the second mag I was looking for maximum reliability and I could find no evidence to support that the II was more reliable than the III other than the II has been around longer.

Just my 2c for what it's worth
Click to expand...


Walt, I always respect your opinions. However this is what Klaus said to me in writing and I quote him verbatim:

"Only the output section is different in the two Plasma CDI versions. The power supply and all logic is the same. I don't see many failures in the output configuration. One could say that the longer spark erodes the spark plugs faster and stresses the high tension wires and coils more on the Plasma 111".

Unless I am mistaken I think this is the manufacturer stating quite clearly that the coil failure rate is higher on the Plasma 111 (which is what you would expect with a longer duration spark).

Additionally, I think that individual reports of failures (or successes) are interesting but I must admit I'm influenced more by the comments of a major engine builder who has installed hundreds of both units and is therefore in a position to have the sort of feedback that would provide a bigger picture.

Incidentally, now that you have been running both systems side by side for a longer period of time do you have any further data that would suggest that the Plasma 111 provides you with any improved performance whatsoever (smoothness of running, increased engine power, fuel savings, etc) over the Plasma 11 when you switch from one side to the other.

I note that back in 2007 when asked the same question on VansAirforce you stated: "Well after careful evalution between the LSE II/III I've concluded I can't really tell the difference".

Now I must admit that because you were the only person I knew with a Plasma 11 on one side and a Plasma 111 on the other side (and therefore in a unique position to draw a direct comparison) I was VERY influenced by that information.
 
Last edited:
On this subject is there a recommended replacement interval for the coils and wires on a Plasma III ? I don't recall ever reading anything on this.
 
Captain Avgas said:
Walt, I always respect your opinions. However this is what Klaus said to me in writing and I quote him verbatim:

"Only the output section is different in the two Plasma CDI versions. The power supply and all logic is the same. I don't see many failures in the output configuration. One could say that the longer spark erodes the spark plugs faster and stresses the high tension wires and coils more on the Plasma 111".

Unless I am mistaken I think this is the manufacturer stating quite clearly that the coil failure rate is higher on the Plasma 111 (which is what you would expect with a longer duration spark).

Additionally, I think that individual reports of failures (or successes) are interesting but I must admit I'm influenced more by the comments of a major engine builder who has installed hundreds of both units and is therefore in a position to have the sort of feedback that would provide a bigger picture.

Incidentally, now that you have been running both systems side by side for a longer period of time do you have any further data that would suggest that the Plasma 111 provides you with any improved performance whatsoever (smoothness of running, increased engine power, fuel savings, etc) over the Plasma 11 when you switch from one side to the other.

I note that back in 2007 when asked the same question on VansAirforce you stated: "Well after careful evalution between the LSE II/III I've concluded I can't really tell the difference".

Now I must admit that because you were the only person I knew with a Plasma 11 on one side and a Plasma 111 on the other side (and therefore in a unique position to draw a direct comparison) I was VERY influenced by that information.
Click to expand...

Well after 2 more years of very careful very non-scientific evalution I can definately say "I still can't tell the difference". That doesn't mean there isn't one just that I have not been able to tell (or do I care enough to do any further testing) any difference between the II and III. If I was doing it again I would just go with 2 LSI II's purely from a maintenance standpoint so you could swap boxes easier for troubleshooting.

I will say now that I have switched to AFP FI the motor is smoother than ever. I always run LOP now which is especially nice in this heat (95+). Just today cruising at 2350/20" at 6gph cht's were 280, egt's around 1330 (70 lop on the richest) oil temp at 180.

I do run Iridium plugs all around, I feel like they do run better (smoother) than the std plugs plus they are holding up very well and not eroding near as fast as std plugs.
 
Ron Lee said:
On this subject is there a recommended replacement interval for the coils and wires on a Plasma III ? I don't recall ever reading anything on this.
Click to expand...

Yes there is a recommended replacement time for the wires but not the coils.

LSE recommends high tension lead replacement every 500 hours or every three years whichever comes first, independent of the ignition source
 
Walt said:
Well after 2 more years of very careful very non-scientific evalution I can definately say "I still can't tell the difference". That doesn't mean there isn't one just that I have not been able to tell (or do I care enough to do any further testing) any difference between the II and III. If I was doing it again I would just go with 2 LSI II's purely from a maintenance standpoint so you could swap boxes easier for troubleshooting.
Click to expand...

Walt, that's very interesting information but maybe not really all that surprising. LightSpeed makes lots of claims for the Plasma 111 with its longer spark duration but they have never provided any empirical test data (at least not that I can find on their website) that proves the Plasma 111 generates any real performance gains over the Plasma 11.

Quite often technologies that provide greater efficiencies in car engines running at higher RPM, higher cylinder pressures, and at extreme mixtures, fail to provide similar benefits in a Lycoming engine which chugs along at a very slow RPM in a very narrow RPM range. Multiple valves are a typical example. Judging from your observations and from the lack of any real data to the contrary it may well be that the longer duration spark is one of those technologies.

All that is known at the moment with any certainty is that the longer duration spark tends to chew through ignition leads and coils at a faster rate (and that the system costs more, and weighs more).

It may well be that after the Plasma 11 has produced 10 degrees of high energy spark the fire is well and truly lit in a Lycoming (if the fire is going to light at all)....the additional 10 degrees of spark produced by a Plasma 111 may do nothing. I'll continue to wonder about that until some-one produces some real comparative data compiled in a scientifically controlled way on a Lycoming. Until that time your observations and testing are probably as good as any going at the moment.;)
 
Captain Avgas said:
The failure rate on the Plasma 111 units, including failed ignition coils, is higher than on the Plasma 11 units. LightSpeed themselves acknowledge this fact (if you bother to ask them...which I did).

I also had extensive discussions on this specific subject with one of the most respected (and largest) Experimental engine builders in the market place (a company that has installed literally hundreds of these units) and they confirmed the same information.
Click to expand...

I do believe I specifically mentioned the exception of additional resistance heating overcoming passive heat rejection to be a failure cause. Did you get any information during your discussions with either Lightspeed or the engine builder as to what was the specific cause of the coil failures? These coils already operate in a hot environment, and are heat stressed from the word go. Additional spark dwell will certainly increase electrical heating in the coil and could conceivably push them into the thermal danger zone. Personally, I would be a little surprised if they were operating that close the edge, but we've seen it before, it is possible.
 
COILS

Speaking of "heat soaked coils", has anyone mounted them somehwhere cooler than on top of the engine in probably the hottest place possible, as suggested by the manufacturer? (!)
Has this resulted in a better life span?
 
RVadmirer said:
.. on top of the engine in probably the hottest place possible, as suggested by the manufacturer? (!)
Click to expand...

This is the hottest location ONLY after shutdown when engine is NOT running. When the engine is running, temperature at that location should be around ambient as airflow is downward.
 
Ah yeah...!

Yes William, that's rather obvious. But the heat after shutdown can be amazing. Can't hardly touch my cowls directly over the cylinders for 5-10 minutes and that is where the coils are sitting, hence my concern. I run a fan through them at home to enhance the cool down and extend the coil life a bit.......
Seems like there are better places to mount the coils? :rolleyes:
 
On my RV-10, the failure mode was the coil

I started this thread so I thought some people might be interested to know what I found.

In the six cylinder LSE design there are three coils (one for cyl 1 and 2, a second for 3 and 4, and a third for 5 and 6). I swapped two of the coils and the problem moved along with the suspected bad coil.

In this particular case, it was the coil for cylinders 3 and 4 that failed.

About $80 from LSE to replace it. I ordered two.

Airplane is 18 months old and has just under 250 hours on it.
 
I have dual Plasma II and mounted 2 coils on top of the engine (cool while engine is running, but wet if flying in rain!) and 2 on the engine mount (hot while engine is running but dry if flying in rain!). I am not flying yet, so I have no idea what the temperatures are in those area's, but I guess with the coils in two different locations, I should have the most reliable set up.

BTW, has anybody had any problems when the connections of the coils get wet in the rain?

Regards, Tonny.
 
I have had several coils fail. According to Klaus, its the weakest point in the system. Further, he is theorizing that the coils are failing due to the increased resistance caused by a widening gap noticed mostly when using NGK plugs. THis was news to me today when discussing it with him. He recommended I go to the Densso or better the Iridium plugs for a reduced wear gap, and see if I continue to see failures. I seem to loose one about one every year or couple hundred hours.
My symptoms are easy to spot and I only loose one side of a coil. First I notice my engine monitor giving all kinds of whacky readings on all sensors intermitently. A few hours later, I loose one side of a coil.
 
Last edited:
Kahuna said:
I.... According to Klaus, its the weakest point in the system. Further, his is theorizing that the coils are failing due to the increased resistance caused by a widening gap noticed mostly when using NGK plugs...
Click to expand...
I would agree with Klaus. Those coils should be pretty bulletproof, unless they start arcing internally and breakdown the wire insulation. At some point the electrons would rather jump the insulation than jump that increasing spark plug gap.
 
Klaus may be right :eek: I've been running the LSII for almost 1200 hrs and the LSIII for about 700 hrs and have had zero coil failures. I've also been running the Denso IK27 since the beginning.
 
Beginning a couple of weeks ago, I noticed that my #1 EGT was running a bit higher than normal. It's always run hotter than the others by a large margin (100-125 degrees), and I was planning to swap probes and see if the high temp moved with the probe. I also noted that, in order to keep the #1 EGT below 1400 degrees, I had to run the fuel flow at 9gph or higher at my usual power settings. Hmmm ...

I flew a short hop on Friday and all was well, except for the anomaly noted above. On Saturday, I offered a ride to a guy and strapped him in. We taxied to the end of the runway and I did my run-up. Left mag, OK. LSE, not so much. Sputtering and big rpm drop. We taxied back to the hangar to fly another day.

I un-cowled and checked the wiring. All looked fine. Pulled the plugs, expecting to find some lead deposits, but all looked clean with just some carbon buildup.

The auto plugs (standard ones supplied with the LSE unit) measured at the large end of the gap recommendation (.034"). These plugs have 145 hours on them.

I wrote to Klaus today and got back a response as has been mentioned here and elsewhere -- at 145 hours on the stock plugs, a coil might have gone belly-up. So, I just ordered new plugs and now I'll have to figure out which coil went bad. A phone call to Klaus got me started in tracking down the gremlin.

Who knew that the plugs had to be replaced so often?? I've owned lots of cars over the years, and can't think of a single one that I've EVER replaced the spark plugs in ...
 
Ron Lee said:
Have you seen this chart Don?

http://www.lightspeedengineering.com/Manuals/Troubleshoot.htm
Click to expand...

Yes, Ron, I did. And when I saw something about using an automotive timing light and measuring resistance through the coils, I knew that I was out of my league. I built the plane. I hooked up the engine. I ran the wires from the panel to the engine probes. But I know nothing about engines and am only slowly learning as I go. As Harry Callihan famously said, "A man's gotta know his limitations."

Sometimes taking a short cut directly to the source saves a lot of time and frustration, and a phone call to Klaus seems to have gotten me off to a start.

Thanks for pointing out the flow chart.
 
You must log in or register to reply here.
Back
Top