Ok guys, I have experienced my first problem with my DA-50. I have called DA and have a plan for resolution, but thought maybe you guys can help out in the process. Quick update - I replaced the fuel valve with a fuel dot. Ran two tanks of 24 oz of fuel through the engine at 32-1 using lawnboy ash less. This was the last of the fuel to get past the five gallon point. All ran perfect. I went to the field and started the engine for the first test flight after doing repairs from the DS with the fuel valve. The engine started and then stopped due to trying to goose the throttle too early before it warmed up. I then could not get the engine started after that.

I pulled the plug and it was obviously flooded with a very wet plug. I cleaned the plug and then tried to start. It would only pop and sputter but it just wouldn't catch. This wore my arm out so I got the Megatron starter out and this only flooded the engine repeatedly. I had set the low end a bit more to the lean side during the test run and all had worked fine with a good low idle and a solid run up to WOT. I pulled the plug again and cleaned and then checked for spark. No spark. I pulled the plug again and cleaned and this time allowed to dry out over night. The engine started right up today and ran fine. I shut it down and then tried to start again only it wouldn't start. Arrgh!

I pulled the plug and cleaned it again and checked the spark again. No spark. I checked the spark by holding the plug against the jug and then turned the engine as though trying to start. No spark. Hm........ My ignition battery is a 1100 mah NiCd four pack and it showed 5.1 volts. I occasionally got a pop but again the engine acted like it just wouldn't catch. If I advanced the throttle at all it would stop popping and flood. I then tried resetting the needles after talking with DA. I used 1 and 1/2 turn on the low end and 1 7/8 turn on the high end per DA. This did not help. Just to be sure about the settings, I used full turns and not half turns on the needles.

So here is what we are doing going forward. I have ordered two new plugs from DA. Hope to have in a couple days. If this does not resolve the problem then I am going to send the ignition in for testing. If this does not resolve the problem then I will send the engine and the ignition in. I was still using a 32/1 mixture when all this happened. I am right at the point where I can now begin to use amsoil. I also checked all the wiring to make sure there were no loose connections.

To date the engine has ran very well with no problems until I encountered a problem with the fuel valve. I re-plumbed all the fuel lines and as I said, ran two 24 oz tanks on the ground to be sure all checked out. I ran the test at about 1/4 throttle and changed the rpms at times with the cowling off and in the shade.

Any ideas on what could be causing this?

It sounds to me like the plug is just fowled.
I would think after you get the new spark plug in it it will run good.

Just curious, did you use a loaded meter to check your ignition battery?
That has to be frustrating, good luck!

I don't fly if my battery is under 6volts with a loaded 1amp meter for 20 seconds. 5.1 volts without a load sounds dead to me....
RickP

Exactly what I'm thinking.

If the new spark plugs don't help ... I would definitely send the ignition module to DA for a check.

I had the same problem at the end of last season ... hard to start ... had to use an electric starter.
The problem seemed intermittent ... changed plugs etc. as you are doing.
Finally the engine just quit in flight at the bottom of a loop. Sent the whole engine back to DA ... they found a bad ignition module.

I was on my third ignition module after only three gallons of gas. The original module did not work right out of the box.

On the bright side ... now that I have six gallons of gas thru it, it starts runs and idles fine. I had the stall problem before I had used five gallons of gas.


Good luck !

Well guys I think you may be on to something. I pulled the directions again on the engine and the directions say to not fly at 5 volts or below. I used a volt meter that provided load and it pulled me down to 4.9 volts. I think I have a combination of possibly two simple problems, I hope . A low ignition battery and a fouled plug. I hope It's not the ignition module as Mustang Fan encountered. I know DA would fix or replace which is not the issue. None of us like the hassle of pulling, packaging and waiting. I would love it if this turns out to be the two things mentioned. I am going to test again today and will provide an update. Maybe just letting the plug dry out overnight and recharging the battery will solve the problem. Whats interesting is that the engine started immediately yesterday, but after the ignition was on for a while all I could get was the pop and sputter and then no spark. Thats the part that concerns me as MustangFan experienced. The problem seems to be intermittent, but the lack of spark could be from the plug fouling out after getting all wet. and the low voltage. Man I hope thats all it was. Will see!

Thanks for the replies.

I accidentally flew my ignition battery down last week. The engine started cutting out in the air at over half throttle but ran fine below that. I landed and checked my battery. 1.6 volts under load, 3.5 unloaded.
A battery that reads 4.5 volts under a 1 amp load will fly the plane for a long, long time.

Many people don't realize that once you foul a spark plug, it's good only for the trash can. If you pull it, blow it out, and stick it back in like you do a glow plug you'll be rewarded with a sore starting arm.

well, I qualify. and have been rewarded..................I can hardly move my right arm today and I ain't kidding. I will wait on the new plugs and then recharge the battery and then let you guys know. Like I said, I hope this is all there is to the problem.

you may not see a spark. flipping the prop -with that ignition.
the ignition may be fine .
ask DA specifically if you should see a spark and under what conditions.
once a module fails it is failed - but these are typically very good ignitions.

"I can hardly move my right arm today and I ain't kidding."

LOL... Poor Roger I feel your pain. I would bet on the fouled plug but still
make sure your battery pack is fully charged.

Keep us posted!

Serge

Thanks Serge and glad I could provide you some cheap entertainment.

Wouldn't you just know it. Hey, I'm confident the new plug will solve the problem. I'm keeping my fingers crossed. I hesitated posting this because I have been so pleased with the engine and didn't want to start anything. However, I was also wanting to learn, which I am in the process of this problem. This is my first bobble with with the engine and it made me very frustrated. I was determined to get it started so you can imagine. The fact that it would pop every other flip was like working a plug on a pond with a hit every other cast. You just keep trying thinking the next cast or flip is going to be the one. Well, the big one got away this time, but I will be back. Only this time I will be ready for results.

Dick, I didn't see your comments until after hours so I don't know what DA would say about getting a spark from the ignition in the manner tried. I will find out and let you know. It was good to hear that electronic ignition will not give an intermittent spark. I understand from your feedback the ignition is either good or bad. This leads me to believe it's a fouled plug because the engine was popping until it became flooded repeatedly. I'm not going to do anything more until I get the new plug and then we will see. Hope thats all there is too it - that and fully charging the ignition battery.

I've been wondering about this. Why in our engines is a fouled plug only useful for the trash bin while in an aircraft engine (full scale) we clean them all the time. Every annual they get pulled and cleaned with good results, they even sell reconditioned plugs to boot.

I've also cleaned them in my car and lawn mowers with no problems, and yes, they test good in a Champion spark plug tester, you know the kind that cleans them and also puts them under pressure to simulate a combustion chamber. You will find the occasional plug that fails that test under pressure, but would spark normally without being pressurized.

I've never tested the smaller plugs from weed eaters though, and that's the reason I ask why is it ok to clean all those others and not the small weed eater plugs? What's different between them?

Since I had many problems with ignition modules, I ask DA directly if the statement in the "manual" was correct concerning not using BELOW 5.0 vdc OR ABOVE 6.0 vdc.

I was told the module had a greater voltage range than stated, and I need not worry about a 4.8 volt battery or using a 5 cell pack without a regulator. I'm using a 4 cell pack.

Yes the module will spark when the crankshaft is turned ... all you need to do is move the hub back and forth quickly making sure the magnet passes the sensor. Also make sure the sensor is plugged in with the wire color coding lined up ( A message I got from DA).

Now that I have a good module ... no problems have been encountered ! Starting by hand now ... my arm has healed.

Hope this helps !

Good Luck

Well darn, Howard.........Now you have me second guessing the problem. I for sure was not getting a spark and I had used the Megatron starter so it was turning over big time while as I held the plug with insulated pliers on the jug. Yes the wiring was plugged in properly. There was no spark at any time that I tried this, even after cleaning the plug and allowing to dry out. My only hope right now is that the plug was fouled even after cleaning and allowing to dry, which has me wondering.

I'm using a Deluxe JR charge jack switch so I wonder if this too could be a problem. I have attached a picture of the switch used below.

cummings66 raises a good question about why these plugs are so sensitive once fouled. I wish I knew the answer. Anyway, I ordered two of them. Whats interesting is that when I talked with DA they told me that plugs going bad is a pretty rare thing. I don't know, but I will learn from this experience for sure, which is what it's all about.

Hey Roger

Didn't you state you only had two tanks of fuel run though this engine? I can't for the life of me see how two tanks of fuel could foul the spark plug?

I guess your switch could be bad, and worth checking, but I use the same JR switchs for ignition and recevers on all of my planes with no problems.

Hope it's as easy as just installing a new plug.

Sorry if I discouraged you.

But I have checked my module many times by flipping the crankshaft back and forth ... If it sparks ... I know it's good.
Another fellow at my club helped me the first time, and told me to do that. Thats how we found out the first module was bad. (Not even a pop)

Good news is, DA is fast at replacements if you need one. I shipped by two day air, and they returned the same way ... same day turn around.

You do not need to hold the plug to the engine for ground, the cable supplies the ground thru the metal ring of the ignition cable.
Are you getting a good connection at the ground ring of the ignition cable ??? Pushed in all the way is it ???

Good luck !

Stomper, I have right at five gallons through the engine. I had replaced a fuel valve that developed an air leak. After replacing a with fuel dot I then ran two 24 oz tanks of fuel through the engine on a test stand we have at the field. I then put the cowling back on and was going to do a test flight. The engine started and then died and it's been down hill from there. Pops , but won't catch and then floods over and over.

Howard, yes, I did make sure the plug was deep in the connector and checked to make sure the wire was visible inside. I'm making good contact, but that was a good question.

Hopefully I will have the new plug by tomorrow and then can see if this was the problem or if there is more to it.

Roger, I know this will sound a little off base since the engine appears to be flooding. Have you checked the fuel filter screen that is built into the carb. It will catch far more trash than most of the filters we place in line between the tank and carb. It also can keep the motor from starting/running but still let some fuel through which would make the plug look wet. It is very easy to check. When the motor is mounted cylinder down, look on the top of the carb. One large screw is removed, lift up the plate then lift the gasket off of the carb body. You will easily see the filter screen in the carb body.

Good luck on running down your problem
Gary

Gary:

Thanks for the filter screen check explanation.

I will check mine ... just to be sure.

The new plugs ( ordered two) finally came in late today and the ignition is being charged tonight. Will know the verdict tomorrow, Saturday and I will report back on the results. Heres hoping.......[8D]

Roger,

Yesterday I ran 2 gallon of fuel on the ground with my DA. I did the last tank to idle while I was cleaning my garage. During the last run the engine started to idle roughly and finally quited.

I started to get a wore out arms (just like you. lol...) when I decided to check my plug.

The plug was very oily and dirty (carbon). I cleaned the plug with varsoil and put it back.

The engine started right away and ran fine.

Just want to pass the infos.

Serge

Gas, or spark, well i have cleaned many a weedeater and chainsaw plugs. Replaced them in the engine and never missed a lick, I have had to respace the coils on normal ignitions to get a hot spark. A member at our club had a simular problem, found that his battery pack had a broken interal connection and I have had battery packs test good under load but after short use the plane was doing strange things. I discovered one of my cells had gone bad. I would get a new ignition battery to make sure, yours might just be lossing a cell or have a broken connection under the covering.

Will

I had thought it should be possible to clean them, there's not much difference between plugs except sizes. I'm glad to hear you've done it many times.

In any event, I wonder how barryB tried to clean his plugs? There is a right and wrong way to do it, maybe he'll post back how he tried and failed and we can learn from that. As to how I did it, I used the Champion spark plug machine my buddy had, but now that he's passed away I'll have to look for another source. I guess I can ask my A&P to let me use his, we get along well.

As I've been given to understand, certain types of media will wipe out a plug quickly, and others are ok. I.e. I think sand is a no no because it might have a couple particles remain which then fuse and turn into glass when you use it.

Normally on an aviation plug we use a pick if we can to remove the lead deposits. But we always pressure test them afterwards to insure they're going to work in an engine. Just because it sparks does not mean it's good, they can and often will quit under load and that's where the machine was useful because it would place them under a load during testing.

Mission accomplished with success and one improving right arm. I am so glad DA-50 is running perfect again. It was just as many of you had suspected. My ignition battery was low and the plug had fouled. Or, the ignition battery was just low, but I replaced the plug as a precaution anyway.

She started per the book the way she always has. I killed the engine and then restarted several times without any problems. I then leaned out the low end after having reset the needles to factory setting.

All is back to normal with more knowledge gained from the experience. Thanks for your help, suggestions and patience.