Hooked-On-RC

My Feedback: (16)

Here is my observation.

The engine started cutting out half way through the 3rd flight of the day. I have done the following so far and to no avail:

1. opened up cowl to allow for "total" airflow
2. replace the clunk line in the fuel tank
3. changed fuel mixture to use 100:1 Amsoil (previously Redline 40:1)
4. increased richness of high end fuel mixture
5. changed the ignition battery from 1500Mah 4.8 NiCad to 5000Mah (8xAA) NiMh 4.8V

The engine runs flawless with awesome power and great response in the first 2 flights. Half way through the 3rd flight of the day, the engine will cut. This happens even in level flight. I have started to suspect it is #5 since that is the only thing that changes from the 1st to 3rd flight.

Now, I went back to the the DA50 Manual and it says under the Ignition System Section:

Use 4.8 or 6.0 volt batteries only. (We see no significant difference in engine performance
between the two.) The ignition will tolerate the peak charge voltage on these packs. Higher
voltage batteries will damage the ignition system and will void the warranty. We recommend
a 1500 mAh or larger pack. With this size pack, the ignition pack should last longer than your
receiver pack will. If a meter shows 5.0 volts or less, don’t fly. Re-charge. Use a 5.2 to 6.0
volt regulator on packs rated above 6.0 volts.

I am running 4.8V. When fully charged, it is 5+ volt. After 2 flights, my low end battery tester shows 80% (surely less then 5V). Is this my problem?

Jake Ruddy

My Feedback: (40)

Typically if your are having ignition battery problems the engine will start to break up and not just shut off. There is no reason why a 1500 pack won't last all day unless you have a bad pack.

I don't see why you would have changed to amsoil to help troubleshoot the issue.... I would be leaning towards the engine is getting hot although you haven't shared the history.

Can you post a pic of your cowl and "cooling"

How many gallons on the engine?

Has it flown fine in this plane all summer and this is a recent problem?

bubbagates

My Feedback: (32)

I'm leaning towards a bad switch though more info would certainly help.

I think knowing the plug color would certainly help as well

Hooked-On-RC

My Feedback: (16)

Guys,
Sorry I am posting this summary for a friend. I do know that this engine has had issues all summer. I have never seen so many dead sticks landings in one flying season as what this guy has experienced. Some of the information you guys are requesting I do not have, however, I can tell you that the owner changed to amsoil after the break in period of the engine. We all thought at first the engine was overheating and therefore dying however now that the cooling issue has been addressed we do not think this is the problem. Why would the plane fly fantastic with no issues on the first two flights of the day, yet on the third flight it has issues? That is the puzzling part!

bubbagates

My Feedback: (32)

It could be an air leak that is opening enough after the first two flights. Are these flights one right after another or has the engine completely cooled down in between flights. I've seen bad reeds do this, I've seen loose bolts on the engine do this, I've seen the gasket at the front of the engine do this.

Maybe a call to DA is in order

Rcpilot

My Feedback: (78)

Is he putting fuel in the tank BEFORE the 3rd flight?

sweetpea01

My Feedback: (10)

Things I would try that you can do at the field....before sending to DA


1. Wipe the motor completely down so it is clean.
---fly your 2 flights and check for any oil leaks

2. Go with another battery on the ignition. maybe even a lion with a reg
---I've had a battery show good voltage but when the motor starts getting warm it pulls more amps to keep the plugs going, thus the battery couldn't keep up in the amp dept.

3. Change ignitions.
---Always possible the ignition is going bad

4. What type of flying?
---you have not mentioned if you are 3-d or just sunday flying. Try 3+ flights of sunday flying. if it works there, than its obvious you have a heating issue during 3-D

flatlandmike

My Feedback: (17)

Check battery connectors all the way from the battery to switch to kill switch if you have one to ign. Try bypassing all components go strait from battery to ignition do this for the entire day open the hatch to unplug the battery; its only one day so you can do this for every flight.

Try a friends ignition.

Try any other thing that da tells you to.

If you have to send it in send every piece and component to them switch battery ignition kill switch every thing.

Also check to see if you have a stuck ring.

change spark plug.

For me i had some issues like this and it turned out to be a bad throttle servo so maybe try a new differnt servo. Different just in case your current throttle servo is not up to the task of a gas plane.

ckoerner

My Feedback: (2)

The connector on the ignition has known to cause issues.

as722

My Feedback: (1)

The switch, regulator and connectors don't know the difference from first flight to the third flight. It easy to check the battery after each flight. Get a quality voltage meter like fromecos and start there.

Albert

flatlandmike

My Feedback: (17)

You must eliminate things and move to the next thing that could be the problem; you or any one having an issue cNT FIX THE PROBLEM BY assuming some thing is fine. Elictronics do funny things im not saying that they are the problem but they could be.

once you eliminate the components of your ignition system then the problem is in one of three places your ign your engine or your engine setup. 2 of those will be fixed by sending the engine to DA.

Good luck finding your issue hope you get it fixed and have many years of flying out of it like i have.

VNulk

A shot in the dark but have you checked the fuel filter for partial clogging. I had results similar to yours until I began using only white gas or Coleman fuel (no additives) as I found that any lubrication ( I tried many brands) I used caused a loose gelatin to form in the tank and, even though run-up on the ground seemed fine, after only 60 to 90 secs in the air, the engine would quit.

Best to you,

Flyjets

My Feedback: (51)

Hi

I happen to have the exact same problem on a DA50r that used to belong to me now is my Buddies. This motor has been flawless for the past year.

It just dies anytime Power is advanced over 5300 RPM every time.

I personally changed Fuel systems Batteries Clunks and filters. Removed the Carb screen replaced the Spark Plug and still no luck.

DA was called and they said it might have sucked the Gasket between the phenolic Block and the Carb but it was OK.

I have decided it's either the Ignition Module or the Carb has just went bad. The Carb going bad does happen as I have seen this twice in the past.

Best of Luck maybe just send it in.

Ian

sweetpea01

My Feedback: (10)

I disagree here......this would all depend on the time between flights. Anytime electricity is running you generate heat. By the 3rd flight you could be overheating a component.

Let us know what you have tried.

There are alot of easy things to do at the field mentioned in this thread before you send your gear in.

as722

My Feedback: (1)

Electricity doesn't run, current on the other hand does flow. I'm kidding with you but it is easy to check the components for heat after every flight. I don't think the problem is heat if it happens every third flight unless he is flying back to back flights.

Albert

groundhogrob

Actually, the amount of heat generated by most of the solid state, and/or semiconductor circuits is not significant and will be difficult for many modelers to diagnose.
The difference between a components “normal working temp” and one with a problem, requires a technical background as an electrical tech or engineer.. Any temperature changes are only symptoms of the problem and would likely have to be measured with an “infrared” surface reading thermometer. Otherwise your guessing…

Groundhog

as722

My Feedback: (1)

I understand that. While it is true that any component and or semiconductor will generate heat and we don't know what normal is, we still can tell if some thing is getting too hot beyond what normal should be.


Albert

groundhogrob

If you are able to open a "C&H" ignition or other brand, and remove the shrink wrap over the unit to try and put your hand on it, it is true you might be able to determine if it is getting hot, but in the afore mentioned problem, such issues as an ignition unit getting hot (from an internal fault) would be good for maybe two or three flights... AT BEST before the circuit simply ceases to function... If you are indeed able to feel any heat generated by your ignition unit (Provided that "it" is not being warmed by ambient conditions) then your probably not going to fly that ignition unit the next flight because it will be burnt out...
This fellows plane has flown many times with multiple flame outs. Some of us local chaps, are leaning toward the ignition unit, but not because we think its getting hot... only because it seems to be a natural progression of elimination of other issues... Of course, heat generated by the electronics is a separate issue from, another source, heating the ignition unit. such as an extremely hot engine bay, or too close to exhaust.... you get the jest...

AND……not all semiconductors generate heat. The ones bolted to a heat sink usually get warm as they should.....while other circuits and components die under heat.... again you may be guessing, unless you have systematically eliminated all other issues or possibilities....

Groundhog..