More DA 50 problems, arghh it must be me!

[pipercub123]

Hey guys,

I've put about 14 flights on the Airwild 260 since my last crash with her and while the airframe is doing great, the engine is back at it again. I'm not about to risk another engine related crash so I'm really trying to get it to run top notch. I tuned it before I first started flying after the repairs and it has been fine until flight 10 when I had a really hard time starting it the first start up at the field. I had fuel coming out of the exhaust because I was flipping it with the choke on and I think it just kept drawing too much fuel. Than I switched to choke off and just flipped and flipped until it just started right up at high idle without any sputtering. I flew one flight and it flew great.

Today I flew 2 great flights with no probs. It took about 4 flips on choke to start and die, than two off of choke. That's how it usually is the first start of the day. Afterwards she started pretty much the first flip. Third time out it died while throttling up for takeoff. I restarted it and couldn't transition to full throttle. I'd thottle up and it would advance only so much and than the rpms would lower as if I were lowering the throttle. So I had to leave it at 1/4 throttle for a bit and than when it wanted to I could move to half and finally full. I'm guessing a fouled plug. Than it was great and I could let it idle slow for 2 min and than gun it with a good transition. So I flew and I had about one very brief cut out in the air at half throttle that seemed like someone took the spark away and than gave it back really fast. If I weren't paying close attention to it, I could have missed it. There was no bogging or anything. Than I came in after a few more min and fueled back up. Once started I ran it up and it did the same thing just didn't take as long for it to go away. I flew again keeping it high in case of trouble. In the air it did one slight split second cut out as it did before and it went to die a few min later on landing and than it caught itself thank goodness.

Back safe on the ground, I let it idle much slower than normal and tried to get it to foul or die out for about 3 min. Than I throttled up slowly expecting hesitation and had nothing.

I've been shutting the engine down using the throttle plate after flying as I normally do with glow engines. I didn't bother buying an electronic kill switch so find it easier to use the servo. Is this bad? It's been fine for the last 6 gal. All I can think of is that the plug fouls when I'm at idle or use the throttle plate to kill it.

I'm running Amsoil Sabre at 50:1 and I'm thinking this is too rich even though I tuned the high needle for peak and than tuned the low until it'd quit 4 cycling by dropping the throttle down until the exhaust note changes and than leaning and repeating until at idle. Than I richened the high end until I got a good transition. I believe this is the proper way. I have some pics of the plug. It appears to be better in the middle and the edges and threads are dirty.

I'm thinking about going back to the 80:1 that I did run in it right after break in as I never had problems with plug fouling that I could remember. I did notice scratching on the cylinder wall and that's why I went to the 50:1. I have fuel filters and I don't fly in dusty areas. When I was running on 80:1, I aimed to keep the head temps around 200 on the ground. Is this a good range for gassers? What's the highest temp you can run and what's the lowest? I know you have to stay within these limits so you run at proper temp. I have what I feel to be plenty of cooling with the cowl.

Am I not adjusting the low end right? Perhaps if I want to run 50:1, I should go to Dominator as I know Sabre isn't recommended for 50:1. I'm sure my engine has a bunch of carbon in it if the plug is looking dirty. I'm planning on sending it into DA in about a month as the flying season here is getting towards an end.

Thanks for the help.

[hawk21]

I had trouble using amsoil saber 50:1 with cm6 spark plugs on a bme 110 they keep fouling every few flights, my friend use amsoil saber 50:1 and never had a single problem but he is also using a different spark plug (FPE 3.2)

[66stang]

Make sure nothings going on with the fuel tank. It could be the clunk. also the ignition module might be cutting out on you.

[gutopila]

Looks like the fouling on the spark plug is the problem. The spark of the ignition doesn't have a straight line, it's goes to the side.

Try to change the plug, and after a day of flight examine it

[mccrind]

I've had a solid year of problems with my DA, and the sounded just like yours. In desperation I installed a new carb (DL, none the less!) and now my motor runs perfect. I'm running 40:1 Stihl and almost scared to go 50:1 in case those gremlins should be fed after midnight!

[en1]

that plug looks too rich as the porcelin is clean and white cause it isnt getting hot enough and gets washed clean by the unburned fuel . it should have a carmel brown dry look to the electrode and porcelin. either you have a carb problem or a ignition that is breaking down. the erratic nature you describe of the problem would lead me to the ignition. Have you contacted DA yet ? I am sure they would be very helpfull in solving the problem. Also make sure you have an NGK CM6 spark plug I cant tell from the picture what it is. Good Luck ...

[cowtown flyer]

Hey there,

I've had a few starting problems with my engine too. I eventually realized that the head bolts had come loose. In fact, 3 of them sheared off in the air - that's how I discovered the problem. Anyway, I was sucking air. I replaced the aluminum bolts with steel.

Now days, I find that I have to slightly adjust the low end almost every day out. There seems to be a fine line between ease of starting and smooth transition. If I richen it up a bit it starts great but dies or doesn't transition nicely with throttle. If I lean it out, it transitions great but I have a hell of a time getting started. It's like walking a tight rope.

Originally after choking, the thing would start on the second or third flip - good luck with that now.

I'm running Amsoil Intercepter at 50:1 and have about 60 hours on the engine. If anybody has any tips I'd sure like to hear them.

Cheers

[pe reivers]

	Quote: Originally Posted by en1
	that plug looks too rich as the porcelin is clean and white cause it isnt getting hot enough and gets washed clean by the unburned fuel . snip...

That's meant as a joke isn't it?

In general:
If a plug has a white top, I would inspect it down to where the isolator meets the plug body. If need be take the plug apart (destroy it). If there is a narrow black ring on the isolator, mixture is OK.
The coked up mass plug body points to a rich mixture though, and that would mean the plug is too hot. That Amsoil does the engine no good I am afraid.

Problems in time may arise if the carb suction line has no decent filter and/or a T-line for fueling. This causes either the internal carb filter to clog up, or air leaks from the T-fuel dot. If the engine runs better on the ground than in the air, the carb reference pressure is the problem, which can be solved using a static pressure tube. (google for pitot tube, static pressure part)

[en1]

[quote=pe reivers;589629]That's meant as a joke isn't it?

In general:
If a plug has a white top, I would inspect it down to where the isolator meets the plug body. If need be take the plug apart (destroy it). If there is a narrow black ring on the isolator, mixture is OK.
The coked up mass plug body points to a rich mixture though, and that would mean the plug is too hot. That Amsoil does the engine no good I am afraid.
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NO not joking , You even state that the plug is rich as well then go off on an airleak thing then to a pressure problem blah blah .... If you had read my post you would have read to CONTACT DA about an ignition problem before trying to adjust it out with fuel mixture. AND it is not necessary to DESTROY a spark plug to tell the fuel mixture. I will not repost to this again so no reply is necessary, I was only trying to help pipercub123 figure out what is wrong with his engine.
I still think you need to check the ignition system AND DONT DESTROY the spark plug to check it, it is plainly visible on the plug as to the mixture when tuned right regardless of what people may say. cause obviously they dont think before talking. once again Good Luck pipercub123

[pipercub123]

LOL, no way am I going to destroy a $6 plug that is only a few hrs old. I had a heck of a time finding someone who could order the plug locally at an affordable price. I say affordable because other places like TBM for one wants about twice that for a plug. Sorry to call out TBM, but why so much for a plug? Plus I'd probably shatter the ceramic and cut off my finger with the pieces.

Anyway I'm going to fly today because I can't stop flying as I'm addicted! I'm going to toss the 50:1 as DA doesn't recommend it and that sucker is getting 100:1. YEEEAH BABY! Than the naughty little thing is going back to DA when the first snowflakes fall becaues that's when I break out my heli for winter fun! LOL, naughty little thing.

[Al Lewis]

You never stated what the plane was doing when you experienced the problem in flight. It could well be a metering issue. As for going to 100:1, well burn it up if you like. Sounds like you need to have someone with experience tune your engine and then fly it to see what is going on when. Other then that you have a half dozen things that could be causing it.

[BOSSIER_ROB]

	Quote: Originally Posted by Al Lewis
	You never stated what the plane was doing when you experienced the problem in flight. It could well be a metering issue. As for going to 100:1, well burn it up if you like. Sounds like you need to have someone with experience tune your engine and then fly it to see what is going on when. Other then that you have a half dozen things that could be causing it.

Al, that's good advise.Amsoil Saber is meant to be run at 100:1 and although it'll be better for you motor to run it a little richer, say 80:1, 50:1 will foul plugs for sure. 100:1 just seems too low for my taste even though I used to run it at that ratio without problems. I did recently switch from Amsoil to Belray and have noticed that even with a higher oil ratio, my plugs in my 150 on Belray 80:1 didn't look near as dirty as the plugs in my 100 did on Amsoil 100:1. It does seem, to me, that it burns cleaner and you get the extra oil for protection. It also does sound like you may have an air leak, though. Your plug indicates a ritch high end or too much oil, but the low could be lean causing it to hesitate during throttle advance. Look for any signs of leak stains around your cylinder head and carb block. Check all of your fuel lines and tank plumbing. If you use a "T" to split your carb line to fill as well, toss it and go with a three line set up. If you cant find any signs of air leaks, ritchen your low end ever so slightly to see if performance improves. Don't expect to just start it up and advance the throttle to full without it sagging during transition. Let it warm up for 30 seconds to a minute, slowly advance throttle to clear it and get the temp up, then idle back and advance it quick a time or two. If it still hesitates to advance, it's low end lean or sucking air somewhere. Look for the simplest things first before you start going crazy looking for something complicated. If it's that bad, it's time to go to DA for troubleshooting and maintenance. Hope you catch it before it costs you an airplane. Good luck!

[Panzlflyer]

Ignition pack??? Seen that many times, all the needle fiddling doesnt fix that or a bad switch/loose wire especially if you use the stock DA power poles

[pipercub123]

Yeah, I've got all stock connectors except for the area that I had to splice in for the switch. I soldered that and I've checked all connections for resistance and continuity. As for the pack, it's a brand new Hobbico 4.8v 2000 mah high draw style and that's seems fine to me.

As for the hesitation, I'm not getting it until after a flight right after I refuel and the engine is still warm. I can let it idle to warm up a bit and she still hesitates until I advance to the highest throttle it'll go and let it run for a minute. I always let it warm up on the first start of the day because I want to let everything expand to normal before revving it up high.

As for the tuning, I tuned that mother's high end until it peaked and dropped off and than went back to peak. I than backed off the trottle until it 4 cycles and lean the low, bump it down and lean some more and so on until it idles and 2 cycles. Than I open the high end until it transitions fine. I check full throttle for a minute or so to see if it will hold and it's fine. I let it idle for about two minutes and gun it too full and it transitions with no hesitation. While flying there is no sagging on uplines, no change in knife edge on either side, during inverted, or outside loops. I was flying knife edge figure eights for about 5 min with no problem. During a descent at idle, it doesn't seem to pop much as the rpms go up and come down. There's a very slight popping, but it is very slight and isn't too obvious unless you really listen to it. There's no burbling at all. I check the temp after landing and the bottom of the cylinder at the front is about 170-180. The exhaust side is close to 220 and has gotten higher since using the Amsoil at 100:1.

I flew 3 flights with no problems. Than every flight afterwards I'd have to work it up to full throttle on the ground. By the sixth flight, it wouldn't even start and took about 4 min of choke on with an immediate pop and than a start off from choke with an immediate die out. Finally after leaving it on half 1/3 throttle while starting, it started and stayed running.

How do I get my low end perfect? Please check out some pics of my carbon build up. I have about 14 or so flights since the rebuild and the new exhaust is already covered in carbon, a very thin but carboned up layer. Is this normal? How can my plane fly great in the air and the only symptons be poor transitioning after refueling until it runs for a minute or so?

One thing I'm going to get some Belray oil and I'm not sure if it'll be H1R or the mc1. I'm leading towards the Mc1. Amsoil, if you ask me leads to carbon and a very pickey engine. It seems like the needles are very sensitive. She ran great on break in oil!

Enjoy the pics guys, I don't think my engine is too far out of wack. I mean, how can it fly really great in the air with no burbling and only a very very slight and quiet popping when on a down line at idle? I kept leaning the low end and still experienced the slight popping. If I lean too much it gets crappy in knife edge. I have a hole in the firewall for the pressure build up too.

Man, glow engines are so freakin easy!

I'm going to keep trying what I can so I don't miss out on flying, but like I said before as soon as winter comes this engine is going back to DA.

[BOSSIER_ROB]

Damn I forgot about that. Good call! . The stock DA Powerpoles are st. If you have those on your ignition system, cut them off and use a deans plug or something other than those. That could absolutely be a problem with intermitent ignition cut out, if that is what you're experiencing. If it's running fine, then cuts out( not to be confused with burbling) and comes back, it's ignition related and you should start by junking the power poles first, if you have those.


EDIT: I was typing while you were posting and just saw your info. That puppy is gunked up. Switch to belray. MC-1 is good but a lot of people are switching to the newer HR-1 and swear by it. Mix one bottle with 5 gallons and you'll be good. I think your plug is just fouling with all that crud. Just for caution, check your front main bearing for leaks. A friend just had some trouble restarting his 150. It would run fine once you got it to crank, but wasn't drawing gas worth a flip to get it started all because of the front bearing, well, that's what DA said when they serviced it. Just give it a look, but I think you're just having fouling issues after seeing those pics. It could use a good cleaning!