pura

My Feedback: (5)

Hi,
I have a DLE 55cc in a Reactor. The engine is pretty new with a few tanks of gas on the plane on a test stand. I began flying it a few weeks ago and all seemed to be fine- engine starts well and runs well in the air, circuits, loops, bunting etc. But when I do an aileron roll it either dies or sputters almost to barely running.
I changed the plug to a CM-6, I checked the fuel line in the tank- friends had suggested that the line may have stretched inside the tank and was getting hung up. All seems to be fine.
I just can't figure out what it could be the cause. My thinking is that it has to be the tank somehow, yet it runs perfectly in most attitudes and the strange thing is that it dies virtually immediately when the plane rolls upside down. I would have guessed that there would be enough fuel in the line to keep int running at least a few moments after the roll.
Does anyone have suggestions how this problem could be corrected?

Thanks,
Bill

Lifer

My Feedback: (1)

Loose electrical connection?

bbbair

You have me confused here... you say that you can do a loop with no problem and yet a roll shuts down the engine... either way you are upside down!??

This does not sound like a fuel issue (there is a pump in the carb) but I'm going to go with 'Lifer' and suggest that there is a loose wire somewhere that the 'Violent' Roll causes to disconnect the power flow (vs a gentle loop ).

Start the engine up and check each wire ... just be careful - that is a big prop that you are swinging.

Zippi

My Feedback: (10)

Had a fellow in our club with a similar problem with his DLE55. It was the diapham for the fuel pump.

earlwb

Also, with a cowled in engine the pump regulator could be getting variations in atmospheric pressure or fluctuations that can cause the regulator to not function correctly. You may need to install a fitting on the regulator cover and route a tube back into the fuselage where the air pressure remains more constant.
ref http://www.prme.nl/forum/viewtopic.p...28f2a9737edc77

ceecrb1

I cant comment exactly on a DLE55 but I had ENDLESS problems with a JC28 which in the end were all down to the valves between the carb and the crank case..
I was suffering dead sticks during an tumbles or violent manouvers and also while inverted you could really hear the rev reducing...
I tried the carb diafragms etc etc.. not saying it wont be this.. but the valves can be shown by cutting in certain manouvers and a bad idle and low end stability.

hobby_man

My Feedback: (8)

My Zenoah G26 and me Syssa 30 used to do that, they were both set too rich on the H, high speed needle

racerman27410

My DLE 30 would die everytime i rolled inverted.... turned out to the metering lever spring was too weak. replaced with genuine Walbro spring and it instantly cured the problem and the engine runs great in all orientations now.

CK1

My Feedback: (60)

+1 , Seen it many times on various engines and airframes . The rolling action disturbs the airflow into the cowl and causes a pressure change that effects an irratic action of the metering diaghram.
It usually doesn't occur on a loop manueuverbecause the pressure change is not as violent and sudden.

I would check the wiring as mentioned in previous posts ,but I would also install the static vent line to the diaghram cover as good measure. It doesn't take long to do and your engine will thank you...

pura

My Feedback: (5)

Hi,
Thanks for all the suggestions. I will have to repair the Reactor before I can try anything more out. I tore out the LG gliding short of the field on the last dead stick.
The Reactor's construction design is going to take some time to put back together!

Bill

jak_kkaall

Hi. By valves between the carb and the crank case you mean the reed block valves that aspire air in the engine? What about them? I know that if they don't close perfectly due to dirt or worn out the carb sputters fuel out through the air intake. How can they influence engine power during rolls? And what do you mean by: "the valves can be shown by cutting in certain manouvers and a bad idle and low end stability" For a second I thought you want to say that the valves can be shown by cutting the engine ) thank Good we don't have to do that...

Can anyone else explain what ceecrb1 means? Thank you!

av8tor1977

My Feedback: (6)

All of the above is good info, and you have some things to check. I would add to try inverting the plane with the engine running on the ground to see what it does. Rock it back and forth as well.

Is your engine mounted cylinder up or down? I have seen this problem on planes with the cylinder pointed upwards if the engine is running too rich. Fuel accumulates in the crankcase, and when you do a roll, that excess fuel drops into the internal airflow and the engine quite suddenly goes stupid rich. Blubbers and sometimes quits if it doesn't clear out the flood. It doesn't do this in a loop because the positive "G"'s and centrifugal force keeps that excess fuel glued to the bottom of the crankcase.

I recently watched a video on Youtube of a glow engine running with a clear backplate. The engine sounded like it was running in a clean two stroke mode, but a surprising amount of raw fuel accumulated in the crankcase while it was running at full throttle.

AV8TOR

jiminthedesert

Other than an electrical connection, make sure your clunk is a large one. If using Tygon type fuel line that is fairly stiff, medium (1/8" ID) should be used as 3/32" is kind of small and may not pass enough fuel. With the tank out make sure the clunk is at least 3/8" away from the back and visually ck. that the clunk is touching the tank as you rotate it 360 deg.