AM6

Hi All.

Thought I'd post a heads up to a potentially dangerous failure that I have had on a DLE 55 - and never experienced before.

The story...

Whilst flying I notice an unusual noise...

Land and inspect - nothing obvious found...suspected cowl vibration/resonance.

Took off again and moments later engine cuts.

Retrieve model and notice that the prop hub had migrated away from from the engine casing ( Front bearing housing).

Start to remove spinner and prop bolts - and the lot falls off!


So - reminder to us all...Take care when starting your engines - and never stand in front whilst running!

Happy landings

Am6.

Lifer

My Feedback: (1)

Always good advice with any engine!

MTK

Looks like hydrogen embrittlement. If I recall someone else had the same thing happen to his 55 several years back. Haven't heard of any more issues with this specific defect until now. If I were to hazard a guess, as many of these engines as are flying, the incidents may be isolated.

Nevertheless, Certainly good advice and I would not want it happening to my 55s. I'm not sure if there is any treatment we consumers could put on the shaft threads to avoid any issues.

manvel

Dear all I am a newcomer both to the site and gas engines. The DLE 55RA is infect my first gas engine and powers my 30% thunder tiger yak 54. I bought the engine a year ago and made 70 flights of ten minutes each. To date I didn't encounter any problems considering the fact that the aircraft is flown at extreme aerobatics flights. I had only one dead-stick because I used a plastic clevis instead of a ball link at the throttle servo arm --big mistake.

The only thing I am concerned about this engine is a particular noise that one hears when you jiggle the spinner or the prop. This noise was present when I took the engine out from the box so it wasn't developed due to wear and tear. Do you think this engine will end up like yours?

Thanks in advance for the info.

captinjohn

China made...its a good chance something will happen...and it will.

Truckracer

My Feedback: (19)

I wouldn't lay awake nights worrying about your 55 crankshaft failing anytime soon. Certainly there have been reports of failures on these engines but the same holds true for other brands (Chinese, German and American) that use the same method of retaining the prop drive hub. Reports of failures are very few and far between but as with all model engines, to be safe, don't stand in front of the prop when reving the engine.

Truckracer

My Feedback: (19)

Oh come on Captn, give it a break about the Chinese produced engines. They're here to stay, at least until we can produce something in mass to compete with them in this country.

manvel

Considering the fact that you can get a DLE 55RA for approx 400 euros and DA 50R for 600 euros from Europe, obviously dle engines would be more attractive for the same power perhaps not reliability. DA has to make customers perceive that a higher cost is for having better quality, performance and reliability. Also it depends on the usage of the engine and perhaps I should opted for a DA for my type of flying.
Thanks guys I will keep you informed how the engine is behaving.

AM6

Manvel

FWIW I have a number of DLE's (and a couple of DL's from the early days).
Apart from one small end failure (unfortunately wiping out cylinder/piston) they have all behaved well.

Nearly all of the minor issues that I have experienced with these engines over the years has been either operator error (mine) or other components (battery/silencer etc.).

Unfortunately however, with this mode of failure, I can see little in the way of being able to check or predict that there 'may' be a problem.
But - with the thousands out there (and the fact that someone often only writes about a problem) it seems likely not to be a common occurance.

I will not be pulling all of my others apart to inspect them - for something that I may not see?

Just be mindfull that this 'can' happen.

Note... In this instance...


Prop was tight (beila 22 x 8).
Prop was drilled/fitted correctly.
Prop was balanced.
Spinner was balanced.
Engine had NEVER had a prop strike.

Hard to see that this was self induced in any way??

Happy Landings.
Am6.

av8tor1977

My Feedback: (6)

The DLE engines occasionally have a crankshaft problem/failure. Not an often enough occurrence to warrant not buying them. They are still a good engine at a good price. Parts are readily available and cheap.

The point here is, stay away from the front of the prop. It always freaks me out to see people doing full power runups, or even just hanging out, in front of a running engine. When I start an engine, I can't WAIT to get behind that puppy where it's safe. I never let other people be in front of nor along side any of my planes/engines when they are running either.

AV8TOR

manvel

Sometimes we take everything for granted and put ourselves in danger without realising the consequences. This is a very important safety issue to observe especially when playing with such powerful engines. This is my first DLE 55 engine and so far no major issues and I am quite happy with it, now time will tell whether this will be the first and the last DLE engine for me. According to other threads the majority of dle engine owners are quite satisfactory and invested in other DLE machines.

manvel

manvel

Dear All, I installed a new engine from the box a DLE55RA for breaking in on my model. After many attempts to flip start the engine and no signs of live I gave up. However, when I coupled the engine with my electric starter the engine sprang to live and works perfectly.

Any clues why it is refusing to hand start.

Thanks & best regards.

Lifer

My Feedback: (1)

Low compression due to a new ring. Pump diaphragm not getting wet from hand flipping, etc. Give it a little running time and it should get better. If not, buy a ring from Bjorn Baal and all should be better.

Truckracer

My Feedback: (19)

Getting fuel through the Walbro carbs can sometimes be a challenge on a new engine. I would suspect this was your problem. Another common problem is a choke plate that is not closing fully. If not closed you could flip forever and probably not get it started. Now that it is running, have you set the needles? How does it start now? Please note this is probably a Walbro carb problem and not a DLE problem. Same thing can happen with any engine.

manvel

Thanks guys, yes it is lack of fuel. The engine is improving and fires after 25 hand flips and getting better. The choke may also was contributing because it is operated with a servo and adjusted to close better.

Thanks and best regards.