How about these plugs?

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mojoe
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How about these plugs?

Post by mojoe » Sun Feb 21, 2016 9:45 am

Yesterday, pulling up behind milk bus my SV 0-540 started running rough and popping. Sounded like fuel igniting in the exhaust pipes. I unloaded my passengers, drove it to the water, and changed the plugs. Felt like a new boat after that. I am hoping to get an experienced opinion on whether there looks like a larger issue, or if that looks like typical lead and oil fouling in an aircraft motor?

Thank you in advance.

The motor was two hours from when my builder recommends changing the plugs.

Looks to me like we got the #3 upper and lower mixed up.
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Re: How about these plugs?

Post by Hardtail » Sun Feb 21, 2016 10:13 am

I would say #1 was fouled completely and #5 not far behind, if you were to use the mixture control with a EGT and CHT gauge you could run a little leaner and hotter which will burn off the fouling, or just carry extra plugs like you did, however if that is a new top end and rings are not seated in yet add some Mystery Marvel Oil to your oil and some in the gas, will help get the ring seated.
If that is an older engine do a compression check and that will tell you if you need to change those 2 jugs. JMO

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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 10:41 am

Thank you Hardtail.

Has 173 hrs since complete overhaul so should be seated.

Without CHT and EGT gauges I am afraid to lean it out any. Builder said he sets them up to be right at WOT and anything below that will be rich. I have been trying to RUN it lately but not really safe too. Runs 30+ at 2100 in shallow water. Runs dry loaded (3 adults cooler and 30gals) at 2200.

As long as it looks like what should happen set up rich, I will trust the builder on the mixture and just keep an extra set of plugs and ride on.
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Re: How about these plugs?

Post by Hardtail » Sun Feb 21, 2016 11:43 am

I would say that you are still getting oil blow-by the rings, Mystery marvel oil should help that out, do a fresh oil change with 1 quart mystery marvel or 20% , and add 4 ounces Mystery Marvel to 10 gallons of gas, I have been doing that since "93" when I bought an airplane with a fresh rebuild flew it for 25 years and no issues, now I still do it with my 0 360 on the airboat, at 73 Tach hours I put on 2 new Chrome jugs from outlaw engines, now I have 173 Tach hours, since the last oil change at 106 hours I've added 2 quarts and still have 6 quarts, before I go out again I'm going to do an oil change, the way we run Airboats I think 75 hours is a good average for oil changes, maybe others will chime in. It works for me anyway. The old timer told me about it when I bought the airplane from him, so I've been doing it ever since,,,

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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 12:23 pm

Thank you again.

The builder told me to change the oil every 25 so I do. I know 50 and 100 hrs are what most people (and the manual) go by. I just trust him.

Gonna ask him tomorrow about the Marvel. You have me wondering whether those rings ever fully seated?
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glades cat
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Re: How about these plugs?

Post by glades cat » Sun Feb 21, 2016 3:12 pm

There seems to be some lead deposits on some of the plugs. There is a product made by Alcor called TCP Fuel Treatment that is good for just that. If your engine runs fat and the cyls don't get up to temp and burn the lead off, it may cause build-up and fouling…besides oil fouling also.
http://www.alcorinc.com/index.php/produ ... ditive-qt/
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Re: How about these plugs?

Post by getitdone » Sun Feb 21, 2016 4:47 pm

What year was the overhaul done and which brand of rings?
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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 5:39 pm

Thanks glades cat. I will look into that. Some had more oil than others, and they always have, but they all had yellow lead deposits on the insulator. That was more lead than I'm used to seeing on them. I may run TCP in the winter when it's almost impossible to get my oil over 160.

I ran av gas in my mower once and found that a small amount of lead fouling will cause the plug to foul across the insulator and not spark.

Getitdone: the overhaul was done in 07. I don't think it says on the paperwork, and I never asked, but whatever brand rings Wally typically uses. If it makes any difference, he had the #5 off about a year ago (broke a hold down stud) and he said it looked like the day he did it. The #1 has always been the wettest since day 1. I doubt it ever seated as tight as the rest.

I'm kinda glad this thread is going the direction it is. With the cumulative experience that has already commented and everybody is still talking about blow by, lead, and rings causing the fouling that lead to the "popping of unburnt fuel", I feel relieved. That is what I thought it was, and I'm glad to have not heard different.... Yet.
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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 5:55 pm

I just checked the plugs again. They have about 1 hr on them. Number one and five are slightly oilier than the rest. Typical for this motor. But they all have significant medium to dark yellow deposits on the insulators again. Looks like lead fouling. Is it possible this tank of gas is more leaded then usual? Anyone ever seen that? Or does it mean it is burning fuel differently than it used to?
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Re: How about these plugs?

Post by getitdone » Sun Feb 21, 2016 6:15 pm

mojoe wrote:Thanks glades cat. I will look into that. Some had more oil than others, and they always have, but they all had yellow lead deposits on the insulator. That was more lead than I'm used to seeing on them. I may run TCP in the winter when it's almost impossible to get my oil over 160.

I ran av gas in my mower once and found that a small amount of lead fouling will cause the plug to foul across the insulator and not spark.

Getitdone: the overhaul was done in 07. I don't think it says on the paperwork, and I never asked, but whatever brand rings Wally typically uses. If it makes any difference, he had the #5 off about a year ago (broke a hold down stud) and he said it looked like the day he did it. The #1 has always been the wettest since day 1. I doubt it ever seated as tight as the rest.

I'm kinda glad this thread is going the direction it is. With the cumulative experience that has already commented and everybody is still talking about blow by, lead, and rings causing the fouling that lead to the "popping of unburnt fuel", I feel relieved. That is what I thought it was, and I'm glad to have not heard different.... Yet.
I had the same problem a couple of years ago in (2014) with the oil fouling on just a couple of them with only 126 hours then on chrome rings which were installed new in (2012) during overhaul. And i was told by my engine builder that there was possibly (not 100% sure) were ??????? rings that had suspect revision numbers or something like that. he replaced all six of them just to be safe and under warranty with another brand and it fixed it. I have 183 hours on it now and they have been seated for at least 25-30 hours with the new rings.
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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 6:32 pm

Thank you for the info.

Hmmmmm? I will ask him tomorrow.
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Re: How about these plugs?

Post by glades cat » Sun Feb 21, 2016 7:05 pm

Are those Champion D16?
You may want to try UD16's on the bottom. The U means they have an auxiliary gap in the center electrode. They're supposed to keep the tip cleaner by producing a hotter spark…not necessarily a hotter plug. The added gap works the same way as when you pull a wire off the distributor to clean a plug.
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Re: How about these plugs?

Post by mojoe » Sun Feb 21, 2016 7:31 pm

Yes. D16.

I will look into the UD16 also. Makes sence.
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Re: How about these plugs?

Post by Planeguy » Mon Feb 22, 2016 9:59 am

Just a note, I have cleaned a lot of aircraft engine spark plugs over the years and I have never seen yellow lead. Lead looks like lead (gray metal) and is usually hard to remove (from an aircraft spark plug anyway). I have occasionally seen yellow deposits and they cleaned off pretty easily. I don't know what they were but they weren't lead.

The general rule of thumb for the oil change interval on aircraft is 25 hours for a screen and 50 hours for filters. There are some variations between the different engine manuals. I think the IO-520 manual calls out 50 and 100. Regardless of the interval you use, if the oil is black and the engine is using more than "normal" it is likely past due.

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Re: How about these plugs?

Post by mojoe » Mon Feb 22, 2016 11:59 am

Thank you playing guy.

Hmmm, I always thought lead was yellow on a plug... Won't be the last time I'm wrong. I have been using the 25 hour interval for plugs and oil. It was couple hrs shy of that so I guess it's time. Oil consumption has remained constant or gone down a little over the last 25hrs. Typical qt every 20gal. Lately it seems about qt per 25gals. I will change it anyways.

I haven't run it as much this year since having a baby. Had to fire it up in the yard to heat the oil up cuz it had been a month.
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Re: How about these plugs?

Post by kwanjangnihm » Mon Feb 22, 2016 12:11 pm

I read this the other day on oil change intervals - good info. I change mine every 25 hrs but may go to the 4 month rule. (see below) :thumbleft:

http://generalaviationnews.com/2004/12/ ... e-changed/

It’s the number one oil-related question of all time: “”How often should I change my airplane’s oil?””

Whenever I give a talk, I usually ask the pilots in the audience what they feel is the best oil drain interval for a Lycoming or Continental engine. The answer is always “”50 hours on engines with an oil filter and 25 hours on non-filter equipped engines.”” This is right out of the Lycoming and Continental service bulletins and is almost universally accepted by the aviation community. Unfortunately, many pilots get to the 50 hour part, stop reading and miss the most important part. The engine manufacturers’ entire recommendation is 50 hours or four months, whichever comes first. (In the past, the TCM bulletin stated 50 hours or six months. However, the people I have talked to at TCM recommend changing at four months.)

The 50-hours recommendation is a very good number for aircraft that are flown almost every week and more than 200 hours a year. But we all know that most private aircraft are flown around 100 hours a year, with many of them flown only 50 hours or less. In addition, many of these aircraft sit idle for weeks or even months at a time. For these low usage aircraft, the four-month rule is significantly more important than the 50-hour recommendation.

The reason for the more frequent oil change recommendation on low usage aircraft is quite simple. When an aircraft engine sits idle, it rusts. I have taken used camshafts and lifters, which were first cooked in used oil for several hours at 200?F, and placed them in a controlled environment at 100? with high relative humidity. Within days, you could observe small amounts of rust forming on the lobe surfaces. After a week, the amount of rust was significant on all of the lobe and lifter surfaces.

Obviously this test was more severe than normal service, however whenever your airplane sits for more than a week in a high humidity climate, rust will start to form on the rubbing surfaces. When you start your engine, this very fine rust (iron oxide) material will be washed away in the oil stream. The filter will pick up some of the rust, but most of it is too fine and will remain in the oil. As you continue to fly on this oil, the level of rust continues to increase. As the level goes up, the oil becomes more abrasive. It becomes a lapping compound on your cam and lifter surfaces, which in turn starts the wearing process. Over time, this will lead to a failed camshaft.

By changing oil more frequently, you remove the rust with the oil. This results in a significantly less abrasive oil in the engine, which leads to a better chance of reaching full TBO.

If you live in a very dry climate, the rusting activity will be significantly less than in a high humidity area, so the oil change interval is less important.

Also, Continental engines with the camshaft under the crankshaft are less prone to rusting than the Lycoming engines, which have the camshaft above the crankshaft. When an aircraft with a Lycoming engine sits idle, air comes in through the cowling, which cools down the engine. With the cam in the coolest part of the engine, moisture will condense on the cam surface, which starts the rusting process more quickly.

Another important factor is your oil temperature. Moisture will condense in your engine just from normal heating during the day and cooling at night. If you do not get your oil temperature up to about 180? in flight, you will not boil off the water, which in turn will increase rusting activity.

You are probably thinking that someone who worked for an oil company would recommend more frequent oil changes so that more oil is sold. However, the choice is really quite simple: You can spend more on oil or you can spend more at the engine shop. Oil is a lot cheaper than engine parts.

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985. You can contact him at Visser@GeneralAviationNews.com
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Re: How about these plugs?

Post by Hog Guts » Mon Feb 22, 2016 12:16 pm

Good information thank you


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Re: How about these plugs?

Post by mojoe » Mon Feb 22, 2016 1:05 pm

Great info. Thank you.
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Re: How about these plugs?

Post by mojoe » Mon Feb 22, 2016 1:16 pm

Hmmmmmm? I wonder if the yellow is rust? That oil is probably 8 months old an it's Florida.

This is the longest it has taken me to hit 25 hrs and the first time the plugs fouled out before that. I wonder.

Either way, changing the oil tonight!
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Re: How about these plugs?

Post by mojoe » Mon Feb 22, 2016 7:25 pm

Thank you all for the info.

Talked to the builder today. He thinks that if changing the plugs fixed it, it was likely pre-ignition. If 1 or more cylinders weren't firing due to fouled plugs, the rest would have to work harder. If they got hot enough to ignite the fuel before the spark it would break up like it did.

He thought UD16 made sense although he never uses anything but D16.

If it does it again, he wants to check timing and...

If not.... Run it.

Fresh plugs, fresh oil, a fresh tank of Avgas and ready to run

Thank y'all again!
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Re: How about these plugs?

Post by Hog Guts » Sat Mar 19, 2016 12:32 pm

I liked the way you kept a visual picture of your plugs when you changed them. I did the same today.... Plugs, oil etc..... Does anyone's trained eye see anything that jumps out other than after a year it was time to change the plugs? It's 1-3 and 4-6
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Re: How about these plugs?

Post by 12PSI » Mon Mar 21, 2016 12:26 pm

I think a air cooled engine designed 60+ years ago is gonna burn a little oil, not bashing them, I have one too.

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Re: How about these plugs?

Post by woods and water » Wed Mar 23, 2016 10:19 am

Looks lean on the fuel end but looks to be burning oil the dry plugs the porcelain is a little white you want it like a moca color

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